Archive of Our Own

One

Sergeant Gregory Lestrade wrinkled his nose, trying to ignore the stench of piss and filth. London had its fair share of derelict buildings, forgotten in some recession or other and never restored. Honestly? Most of them needed the sort or urban renewal best provided with a flame-thrower. This one was falling down around his ears: a concrete shell and not much more. Still, they'd had noise complaints from people in some flats nearby, and someone had made enough of a fuss to get a few bobbies in to investigate.

He had a couple of constables on his heels, staring at their surroundings with a healthy dose of fear. Good. Nothing hurt more than losing a beat cop because of some kid off his face on something. One wrong look and the flash of a knife was all it took.

A few steel barrels had been brought in; their foetid contents coaxed into fires in the distant corners. Shadows moved in front of them: the huddled homeless. In theory, Greg knew he should get them to move on. In practice, it was pissing it down outside and they weren't doing any harm. They were the invisible ones: silent as ghosts half-the-time. No, if he had to guess what the noise complaint was about, two dealers had encroached on each other's turf. If they were lucky, it had been a spat and nothing else – loud words, lots of cursing and a judicious retreat.

If not...

Well, it wouldn't be the first corpse Greg had tripped over in his short career, and it would be one less dealer causing trouble on the streets.

'You two head that way. Eyes only. Don't bother anyone. If someone gives you grief, back off, all right?'

'Shouldn't we do something about them?' Collins demanded. He was new. Keen. Had ideas about cleaning up all of London by himself. Greg would bet his month's wages he'd be out of the force before the year was over.

'No.' Higgins rolled her eyes, her smile a slice across her face: brittle and brimming with sarcasm. She'd been working with Greg for a while now. Destined for better things, or would be, if he had any say in it. 'Look, these people? They're not the problem. We're just here to make sure all's clear, got it? Don't bite off more than you can chew. You be all right on your own, Sarge?'

'Yeah. Radio in if you get in trouble.'

'Same goes for you.'

He watched the pair go, Higgins doling out a few life lessons to Collins as they ambled off. Good. All being well, the three of them would be out of here in the hour with nothing but a nice bit of fuck-all to report.

Turning the corner, the toe of Greg's boot caught against something solid and angular: something that complained with a rough groan of annoyance. He stumbled, catching himself against the wall before he fell flat on his face. Wrinkling his nose, he peered down at what he had thought was just a pile of rags.

Now, in the baleful light of his torch, he could see the figure curled up on its side, a hoodie pulled up over its hair and well-worn jeans with ragged hems encasing its legs. It was hard to tell much about the person except that they was painfully thin, all angles wrapped in fabric, and when a pair of silver eyes glared up at him he saw twin dark pools of pupils too dilated for the brightness of the light.

'Here, are you all right?' He eased back, hunkering down just out of arm's reach. God knew what the kid was on, but drugs made people unpredictable, even if they didn't overdose or end up on a bad trip. Messing with human biology always had its problems.

'Go away.'

Greg raised an eyebrow at the posh accent. Clear enunciation, too, as if he suspected Greg to be of sub-standard intelligence. The kid looked too old to be a runaway. Greg would guess he was pushing twenty, maybe a little older. Not homeless, either. He'd probably come here to get high.

'We had a complaint about noise. Fighting. You wouldn't know anything about that, would you?' Greg scanned the area with his torch, noting the delicate turn of the wrists at the jumper's cuffs. Skeletal. No meat on him at all. An addict, then, if Greg had to guess. He had that sallow, thin-skinned look as well, the one that came when the next hit meant more than the next meal. A bad state to be in. 'You got a name?'

The hesitation was just long enough for him to realise he wasn't getting the truth. 'William.'

'All right, "William". Here's how it's going to go. Either you can give us some decent information about what happened here tonight, something I don't already know, or I take you down the station. Have you piss in a cup. How about that?'

He got a look that could have peeled paint, all haughty annoyance. Greg stumbled to his feet, taking a cautious step back as the young man pushed himself into a sitting position, cuffing at his face with his sleeves and giving a sniff.

'Something you don't already know?' he demanded, narrowing his eyes against the glare of the torch. 'Where should I start? With the fact that the two dealers you're looking for are embroiled in a turf war? That one is from Bethnal Green and the other from Shadwell? That, judging by the stains on his clothes, Bethnal spends a lot of time hanging around a bronze sculpture: the verdigris leaves its mark. You might want to check the area near The Lesson. It's the only bronze in that area. Shadwell has a scar along his jaw and suffered pneumonia as a child, as evidenced by a persistent and annoying cough. Is that enough?’

'Er...'

'No? Perhaps you would also like to know that your wife is cheating on you with her yoga instructor? She had part of the mat in her hair when she ironed your shirt. It fell onto the fabric and burned into it, leaving a faint green stain. Could be grass, but it's too unnatural, and the burn pattern matches the shape of plastic fragments commonly found in cheap sporting equipment.'

'What?'

'That should be enough to be going on with, don't you think?'

Greg stammered, managing nothing as the young man got to his feet and tugged at the hem of his hoodie. 'Goodnight, Sergeant.'

With that, he was gone, a pale shadow staggering off into London's wide sprawl, leaving Greg with his mouth hanging open. He should have run after him, slapped him in cuffs... something. Instead, he let him go, shaking his head in disbelief.

It turned out he was right, though, this "William". About the dealers, the statue, all of it. Even the bit about his wife.

Damn it all.

Two

Peeling wallpaper lined the staircase, ribbons of it unravelling like shedding snake skin. This place should have been condemned years ago, but it lived on, housing tenants too poor or too downtrodden to try and get out. That's why he was here with the drug squad. They'd been watching the property for a while, suspecting it as a base of operations for one of the smaller gangs. Production, not distribution. Now, they were moving in to bust the joint.

At least, that had been the plan. Instead, it looked like the bastards knew they were coming. They'd cleaned the place out, leaving nothing but scarred tables and broken furniture in their wake.

'Fuck it,' Greg swore under his breath, watching the gathering storm-clouds on DI Teems’ face. They'd been working towards this for months, keeping it quiet, inching their way ever closer. To realise they'd been rumbled at the last minute set his teeth on edge. Weeks of work down the drain. 'Want me to call it in?'

'Get Forensics in here,' Teems confirmed, waving everyone back towards the threshold so they didn't disturb the scene. 'There'll be plenty for them to analyse. We can at least verify our leads were good, and who knows? Maybe we'll turn up something about where they went.'

Greg nodded, stepping out of the room with his radio halfway to his lips before he realised he was being watched. There, on the landing below and across the stairwell, a lean man with unruly dark curls stood, full lips wrapped around the filter of a cigarette and one arrogant eyebrow lifted in recognition.

The hoodie was gone, replaced by a shirt, well-made but worn and rolled up to the elbows. His legs were clad in what appeared to be the same jeans as when Greg had last seen him, cleaner now, but still tatty. He looked like a posh boy slumming it. Perhaps he was, for all Greg knew. Unlike everyone else in the building, he didn't cower behind the door to his flat or hide his face. Assuming he lived here, of course.

'Did you ever catch Bethnal and Shadwell?'

The drug dealers from before, almost a year ago now. Greg could not help the smile that hooked his lips, sharp and a little wild. 'Red-handed. Ditched the wife, too, though that took a bit longer.'

'Just as well. I doubt she would have reformed.'

Greg pulled a face – a grimace of acknowledgement – before leaning his weight cautiously on the rickety guardrail and letting some of the tension leave his body. 'Don't suppose you want to make up a last name to go with that first one, do you?'

The man who called himself William smiled, cocky and amused. It looked uncomfortable on his face, like he wasn't used to it: feral thing that he was. 'Not particularly. Need help with those ones?' He gestured towards the flat at Greg's back with the cigarette, flicking ash from the tip to melt the plastic carpet underfoot. 'Or will you manage?'

'Hah. You might have been right last time, but it's not like I can get my DI to build a case based on your say-so now, is it?'

'So don't tell him you got it from me. An anonymous source. Your kind do that a lot, don't you?'

'My kind?'

'The police.' William rolled his eyes as if Greg were being spectacularly obtuse. 'Or I could leave you and the lab-coated fools to stomp all over the place like bulls in a china shop and get nothing for your efforts. Your choice.'

Greg hesitated. He'd been right the last time, this mad bugger, but for all he knew he had inside information. Maybe he'd been witness to Bethnal and Shadwell and made the rest of it up. Perhaps he'd been working with them all along. It wasn't as if Greg could go back to his DI and say "Some bloke told me where they've gone." Not if he wanted a promotion any when in the next decade.

And yet...

'What's in it for you? I can't pay you. We don't work like that.'

The man screwed up his nose, raising the cigarette to his lips for one final, deep drag before leaning forward, stubbing it out on the handrail and pitching it down the vertiginous drop of the stairwell. 'I get a few minutes away from the stultifying boredom of my daily existence. How about that? It costs you nothing; all you have to do is listen.'

Greg took a breath, glancing back over his shoulder, watching his DI gesticulate and fuss, practically tearing his hair out. If he was lucky, he might be able to angle it so he never had to explain where he got his information in the first place. 'Go on then.'

'Cookers, not growers. Meth, mostly, with a side job in cutting cocaine. One has half of a degree in chemistry. Dropped out of UCL when he realised there was a fortune to be made in manufacture. The other two are distributors, but the product's good quality. Very good.'

'Speaking from personal experience, are you?' Greg murmured, scribbling in his notebook and shooting a look in William's direction when his only reply was stony silence. 'Go on. What else? You're not telling me anything new at this stage.'

'They got the attention of plenty of the local gangs. There was a bidding war. Mostly, they wanted the chemist. The others were just convenient.' William shrugged. 'They didn't leave because they'd been tipped off to your little raid. They did it to get out of the spotlight.'

Greg sighed, tapping his pencil against the page. 'You live here, don't you? Did you speak to them? Know much about them?'

'They were not very circumspect in their disagreements.' William smirked. 'They had a tendency to fight in the hallways. As for where I live, that's not of any relevance.'

'Isn't it?' Greg bit his lip, shaking his head. He was right, it didn't matter whether William dossed down here or was passing through. Part of him hoped, though, that he didn't make this place his home. It felt like a tenuous existence. Better than the homeless around a blazing barrel, but only just. 'Can I get any names to go with this information? To track them down?'

'The names they use aren't theirs.'

'Oh, like "William" you mean?'

'More like "Fat Gazza" actually.' William leaned forward, taking a deep breath and seemingly settling into himself. He closed his eyes, lashes fluttering as that live-wire body fell still, no longer fidgeting but motionless, as if he were diverting all his energies inwards. He almost looked as if he had fallen asleep, but then those eyes snapped open and a litany of information escaped him in a rush.

'Focus on the chemist. The other two are hangers-on. Find him, and you'll find them. You're wrong about them associating with a gang. They declined all offers, which got them into hot water. Check with UCL for second year drop-outs in their chemistry department. Six foot three and a half, white, brown hair, green eyes. On the chubby side, like a rugby player who's not seen a game for a season or more. Walks with a limp: old knee injury. He'll be heading back to known territory. Somewhere he can still sell his product without treading on toes that will get him killed: Islington, probably.'

'If he's not part of a gang then he's not much good to us. Independents are low priority these days.'

'Idiots. All of you. Independents have no loyalties but to themselves. Book him on production, then make a deal. He'll roll on everyone that's ever tried to obtain his services. That could give you a way in to seven gangs in this area alone.'

William inhaled, his eyes darting from side-to-side as if reading an invisible script. 'Should you wish not to involve the university, the chemist rolls his own cigarettes. Turkish tobacco. His preferred brand is only available in a pair of corner shops in Palmer's Green. Put a watch on them. He'll turn up in a day or two.'

'What, nothing about the mud on his shoes this time?' Greg joked, feeling a little breathless. Islington was more than they'd had to go on half an hour ago.

William huffed, already turning away and slouching off down the stairs, his footsteps clattering as he went. 'Have fun, sergeant.' He looked up, throwing a silver flash of a wink in his direction. 'No need to thank me.'

With that, he was gone.

Three

'Jesus!'

'Not quite. Though I'm flattered.'

Greg gaped. He'd almost not recognised him, mostly because of the blood. It painted a garish splash down William's face and turned his mouth into something monstrous. 'What the fuck happened to you?'

William squinted at him, sagging against the wall of the alley with a groan. 'An altercation. It's really none of your concern, Sergeant. No serious crimes have been committed here, unless you count idiocy.'

'Yours, you mean?' Greg snapped, alarm jangling along his nerves. One of those bright silver eyes had swollen shut, and there was a nasty gash on William’s temple. He looked a right mess, and Greg fumbled for the tiny, inadequate first aid kit he kept on his belt. Not much more than gloves and band-aids, but at least it was better than nothing.

'God, sit down before you fall flat on your face.' He grabbed William's arm, trying to ignore how skinny it felt beneath his grip as he guided him down on to some poor sod's nearby doorstep. Someone with big fists and minimal pity had lain into William, and not that long ago, if he was any judge. The wounds were only just starting to clot.

William hissed as Lestrade ripped open an antiseptic wipe and blotted at the head wound. There was no point in trying to fix the bastard's nose. Not without a handkerchief or a rag or something. There was too much blood. 'Anything broken?' he asked.

'What do you care?' Petulant and sulky was a new look on William. 'Believe it or not, I didn't intend to stumble into your path. I was simply hoping to get home.'

'Where's that?' Greg asked out of habit. He'd almost forgotten about William, hadn't even seen him since back in the stairwell with the bust that wasn't. Yet now that same old fascination return, prickling at his mind. There was something about the kid – man – Greg supposed, that gave him pause. Besides, he was a copper at heart. It was his job to ask questions. What he didn't expect was an actual honest-to-God answer.

'Montague Street.' William sighed, waving a hand down the road. 'It's fine. I'm fine. I can get there myself.'

'Really? Cos you're either high or concussed. Maybe both. You can barely walk straight.' Greg pitched the blood-drenched wipe in a nearby bin and pulled out a small packet of Kleenex. 'Pack those up your nose,' he ordered, deciding the less room he left for argument, the better. 'Give it five minutes, and if you can prove to me you've got enough strength to get home, I'll let you leave.'

'Am I under arrest?' William grumbled, ripping open the tissues and doing as he was told. 'If not, I would consider this unlawful detention.'

'Protective custody,' Greg corrected him. 'Don't be a dickhead. It's me now, or an ambulance in ten minutes when some passer-by reports a bloodied man stumbling about in need of medical assistance. What's it going to be?'

William rolled his eyes, well, one of them anyway, as if Greg were the one relying on his charity, rather than the other way around. A moment later, that gaze flickered to a CCTV camera on the street corner. God alone knew what that was about, but he didn't make any further fuss, sitting on the doorstep with his hands hanging between his spread knees and his head bowed.

The idiot was still using. Maybe it didn't write its story all over him as blatantly as it had that first time, but there were traces of it if you knew where to look: fingerprints of addiction. There was no point in trying to talk to him about it. Greg didn't know him that well, and any concern on his part would be ignored at best. More likely, William would just mock him for having the nerve to give a shit.

Still, he was pretty high-functioning. Either he was more in control of his use than appearances suggested, or he had been turning to drugs for so long that he could appear almost normal while half off-his-face. 'Course, it depended on his drug of choice, too. A stimulant of some kind, if Greg had to guess. Downers made people dopey: that was hard to hide, especially when the person didn't care about concealing what they were doing.

'Are we done?'

'Ah ah,' Greg held out a hand, stopping him before he could get to his feet. 'Not yet. Prove to me you're all right, first.'

'What would you like me to do?' William demanded. 'Say the alphabet backwards while touching my nose?'

'Prick,' Greg grumbled. 'Walk in a straight line. If you can do that, maybe we'll get on to the more advanced stuff.'

William sighed, a great, gusty thing that fluttered the bloody tissue still hanging from his nostrils. Even like that, beaten all to hell, he managed to look haughty as fuck. Greg was starting to think he deserved whatever smackdown he'd received. Git.

'I have a better idea. How about this? You're the oldest sibling in your family. You have one younger brother. He's a disappointment. Your parents are dead and have been for years, but you still serve your country in the hopes of making your mother proud.

‘You don't give a shit what your father ever thought of you. Perhaps he was drunk. Maybe he just lost his temper. He never had your respect. You joined the force because the army wouldn't have you. Probably for the best, you’re too intelligent for cannon fodder. Your wife wanted kids. You've been grateful every day since your divorce that you never agreed to start a family.'

He flicked his hand, giving his head a tiny shake. 'Obvious,' he muttered as if berating himself. 'You moved to the serious crime commission in the last three months, and you think you'll be promoted in the next three. There's a slim chance you're not wrong on that score. Your shoes indicate the change in pay. Better quality. Ironic now you'll be walking the beat less and less. You've not bothered to get a new uniform. You think it's an unnecessary expense as you won't be needing it for much longer: not if you go plain-clothes. It's been mended by someone with questionable sewing skills and stumpy fingers. Possibly yourself. Probably some well-meaning acquaintance.'

William’s voice dropped to a hiss and his good eye narrowed to a slit of annoyance. 'I know everything about you, Sergeant, from the fact you tore all the ligaments in your knee at secondary school to the idea that you would love a pet dog, but don't have space in your flat. The story of your life is written on you for anyone who takes the time to look, but no one does, because in the end you're nothing but a sergeant in a declining police force. Another bobby on the beat. Part of the furniture. The only thing I don't know about you is your name, and since it's irrelevant, I won't bother myself to learn it.'

He got to his feet, those cold eyes sweeping over him as Greg could only stare, his mouth agape. He blinked, his brain cycling through a cluster of random protests, curses and insults, but in the end, William was right. Maybe the bastard had looked him up somewhere, dug into his past.Yet that didn't explain how he knew the current things, like the bit about a promotion and him wishing, more than anything, that he could get a dog.

His voice creaked in his throat, locked around an aborted question of "How?" but it never escaped. Besides, William was already gone, his stride more than a little wobbly as he beat a hasty retreat. Probably just in case Greg decided to finish what someone else had started.

'It's Greg Lestrade!' he hollered, shaking his head in disbelief: the one bit of knowledge he had to give that William hadn't already read off him like he was a short book with big words.

If William heard him, he didn't respond.

Four

'I need to see Detective Inspector Lestrade.'

That voice. Greg stopped with his mug of coffee halfway to his mouth. God, it had been almost eighteen months since he'd heard it last, spitting out his life history like a challenge. Maybe the job was getting to him. He'd assumed William had buggered off out of London. That, or succumbed to whatever drug habit he wore as if it were a crown upon his brow: bold as brass and unapologetic.

Either way, he'd written him off. Now here he was, popping up again like a bad penny, right when Greg was in the middle of a triple murder case. He had a suspect in custody: a good one too. Guilty as sin about something, and it might as well be this. So why did the mere sound of William's voice have Greg questioning his completely logical conclusions?

'You've got the wrong man.'

He groaned, closing his eyes and wondering if he could just ignore the figure who had materialised in his doorway. Pretend he was a ghost, or something. They had the suspect on the ropes. This case was almost wrapped up...

But try as he might, Greg could not be that kind of copper. He never had been one to do what was easy, rather than what was right, and he couldn't start now. 'What do you mean?' he demanded after he'd taken a sip of coffee, opening his eyes to give what he hoped was a superior, doubtful glare. Not that it worked. How could it, when he took in the appearance of the man in front of him?

For all the time he'd known William, in the loosest sense of the word, he'd been a scrawny young man of indeterminate age. Somewhere in his twenties, Greg would guess. He'd been sharp as a knife, his face hollow-cheeked and his bones pressed up against his skin. His hair had been a nest of curls that didn't see a comb very often, and behind that cocky arrogance had been a sense of something wild about to take flight.

The man in front of him now... The word that kept coming to Greg's mind was "honed", like all that scattered potential had pulled itself together into something confident and clever and knowing.

William's silver eyes were clear and bright, while his pale skin carried a suggestion of a tan, as if he had been on holiday a few months back, during England's miserable summer. His hair was artfully scruffy, the kind of mess that took an hour to make look right, and there was not a trace of those jeans.

A long coat hung from his shoulders like a robe, and underneath, Greg could see the lapel of a very expensive, hand-made suit. He'd always suspected William was a posh boy roughing it. Now he had his confirmation.

Still, it was good to see him looking so well.

An arched eyebrow implied he was staring, and Greg gave himself a shake, setting his mug aside and leaning back against his desk. 'Well? What makes you think the man I've got in my interrogation room is innocent?'

'I wouldn't go that far, Lestrade. He simply didn't commit the murders you think he did. He was busy burgling a house in Hampstead at the time.'

'What?' Greg's voice sounded weak, even to his own ears, and he reached up a hand, scrubbing it across his face. 'What do you mean?'

'Angelo Giordano might be a criminal, but he is not a killer. He has a history of petty theft, but this would be his first conviction if the decision were made to press charges. He would be looking at a short prison sentence. Compared to triple murder...' William shrugged, not bothering to state the obvious. 'Has he asked for a lawyer?'

'Yeah, yeah. We're waiting on a public defender now. Look, I can't take your word for this, you know.'

'It's enough for you to start looking, isn't it?'

'That's not going to –'

A tap on the door caught his attention, and Greg looked up to see Sally Donovan hovering on the threshold. She was a constable under DI Bradbury. Good. Keen. Lestrade would have made her a sergeant by now, but Bradbury was an old-fashioned pig, and Sally? Well, she looked like an easy target. Knew how to act it, too, when it was the best way forward, but she had cunning in spades and knew when to put it to good use.

'Sorry,' she said, not looking remotely apologetic, her eyes fixed on William with a bold mixture of curiosity and judgement. 'Am I interrupting?'

'Not really, can I help?'

'Bradbury's calling a meeting with the Chief in an hour. He's putting you on the spot, hoping you'll sink.'

Greg swore, long and low, with great feeling. He should have known Bradbury would pull this shit. He'd been pissed off that Greg, the most junior DI in the place, had the luck to land the triple murder at Covent Garden. It was a big enough crime to be top priority. No doubt he'd told the Chief that Greg had the person responsible. Now if Greg changed his tune, he’d look like an idiot.

‘William, unless you can come up with some proof...'

'Check phone records. Angelo will have been making calls from Hampstead at the time you think he was in Covent Garden killing three people.'

'He was seen!'

'By who?' William narrowed his eyes, his expression twisting in disbelief. 'That can't be all you have to tie him to the scene of the crime, surely? An eye-witness testimony?'

'He's on CCTV, caught two streets away about a half hour after the murders.' Sally crossed her arms, shrugging. 'I've been keeping up with the case. It's the kind of thing I joined the force for. It's why I put up with Bradbury.'

'Someone who looks a little bit like him appeared on grainy CCTV footage, you mean?' William sneered. 'You don't have fingerprints? DNA evidence?'

'The scene is still processing.'

'Who's doing your Forensics, an imbecile?' William shook his head, dismissing whatever defence anyone might raise. 'Never mind. It's irrelevant. Check the phone records, and his oyster card. Once you have that, verify his presence in those locations. I suspect you'll conclude that Angelo could not possibly have been in Covent Garden killing people while simultaneously committing crimes elsewhere.'

'Who the hell do you think you are?' Donovan's expression was all teeth. Lesser men had backed away from that look: a tiger's snarl masquerading as a smile.

'The only thing that matters is that I'm right,' William replied, all cool disdain to Sally's hot annoyance. 'Good day, Inspector.'

He left, his coat whirling with a kind of artless elegance as he strode through the Yard, ignoring the looks he garnered in his wake. Greg watched him go, feeling a bit like he'd been hit by a train.

'Friend of yours, is he?' Sally asked, all thought of rank forgotten. 'Coming in here and telling us how to do our jobs?'

'Yeah, no. Acquaintance. Maybe. I don't think he has friends.' Greg pursed his lips. 'Look, Sally. I know you're in Bradbury's team, but could you do me a favour?'

'What?'

'Do what he said. Run the phone; the oyster card. I don't trust anyone else not to make a pig's ear of it.' He watched the play of emotion across her features, saw the shock and confusion get tamped down hard by the same ethics he himself swore by. She'd no more be a lazy cop than he would, and despite her distrust of a tall, dark stranger bearing answers they didn't want to hear, she couldn't turn her back on the questions William raised.

'On one condition.'

'What?'

'Make me your sergeant.'

Greg tilted his head, giving it a moment's thought. It wouldn't be easy. Bradbury would raise hell, but that only made it more appealing. And at the end of it? Well, he'd have Sally Donovan at his side.

Win-win.

Five

'Montague Street? You sure?'

Sally nodded, giving Greg the side-eye. 'You all right?'

'Yeah, it's... yeah.' He grimaced, jerking his thumb towards his car. 'You coming?'

Sally raised an eloquent eyebrow, her sensible heels tapping on the floor as she followed him, slipping into the passenger seat and doing up her seatbelt. 'Talk,' she ordered. Honestly. Anyone would think she was the DI around here. Not that he could blame her. He might be where the buck stopped, but it was Sally that kept them all on track, filling in the gaps and becoming the glue that held most things together.

'Last I heard, William lived in Montague street.'

He glanced at Sally out of the corner of his eye, watching her sneer. They'd come across William once or twice since Angelo’s arrest, and he and Sally got on like a house on fire: screaming, death, destruction... the works. William deduced every little thing about her and she blew up in his face. 'So, maybe someone's finally put the freak in the ground. It wouldn't surprise me.'

'You just hate that he's always right.'

'No.' She folded her arms. 'I hate that he's a cold prick who only cares about how interesting a crime is. He doesn't see the people. He just sees the puzzle. He'll make witnesses cry to get his answers and wouldn't know compassion if it bit him in the balls.'

'Every time he's given me advice, he's been spot on.' Greg pulled up at a red light, drumming his fingers on the steering wheel. 'How many would've got away if not for him. I'll put up with his –' He waved a hand, unable to find the right words. ' – his whatever if he keeps getting us results.'

'Using him is fair enough, but you care. You always care.' She sighed. 'And he doesn't give a shit about that, just like he won't give a shit that you're worried its him dead in some dingy flat on Montague Street. He doesn't even think enough of you to tell you his real name.' She arched an eyebrow. 'And for some reason, you won't look it up.'

Greg groaned. This was not the first time they'd had the same stupid argument. 'No, I've told you before. That's – it feels like cheating. He'll tell me his name one day.'

'And if he doesn't?'

'Then he'll just be "William" forever, I suppose. It doesn't matter, all right?'

'Well, you never know,' Sally said as they pulled up at the scene: all blue flashing lights and confusion. 'Maybe you'll get to read it on the coroner's report.'

Greg clenched his jaw. He liked Sally, most of the time, but there were occasional days when she was just as harsh as William, brittle and sharp and impossible to manage. He could see she was gearing up for a fight: shoulders tense, her stride as quick and furious as her skirt would allow. He slammed the car door and followed her, nodding to the uniformed officers and making his way up the stairs, dread hollow in his gut.

Someone was shouting. His first thought was some relative of the victim, but they'd been outside, sobbing in the back of an ambulance with a blanket around their shoulders. No, that reedy voice sounded like Anderson, their newest Forensics lead, and only one person made him sound quite so outraged.

'What are you doing here?' Sally demanded, rounding the corner to see William at the doorway to the crime scene. 'Who let you in?'

'I thought you did!' Anderson whined. 'You told me they let you up!'

'No. You assumed. Just like you're assuming there was only one attacker, despite all the evidence to the contrary.' William eased back, giving Sally and Greg the space they needed to take in the scene.

Few murders could be described as pleasant, but at least some of them were clean. This one was nothing like that. Blood arced everywhere, and while there was no weapon in sight, Greg would put his money on a blunt instrument. The body was pulp: smashed, not sliced. Someone, or if William was right, more than one person had been furious at their vic. Now, it was up to them to try and figure out what the hell had happened.

'Look,' he began, jabbing his finger towards William. 'You can't do this. Can't just turn up at crime scenes and tell us what to do.'

'I wouldn't have to if any of you knew how to do your jobs.'

'Shut it.' Greg snapped as Sally and Anderson both squawked in protest. 'Look, I'm serious. This has got to stop. I don't know what you think you're doing, but we don't need your help.'

'You've needed my help from the first time you met me.' William didn't shout. He didn't have to. His words carried, deep and resonant, as if he were the one laying down the law. 'Back when you were a sergeant. Bethnal, Shadwell. Fat Gaz the disappearing chemist. Even now, you're oblivious!' He threw a hand in the air, as if he couldn't believe he was surrounded by such morons. 'What must it be like, being you? How can you live each day without being able to see?'

'That's enough. Either tell me something useful or get out of here.' Greg snapped, aware that Sally was on her radio, calling for uniforms to drag William away, her voice thick with glee.

William raised an eyebrow, not sparing a glance for either Anderson or Sally. They were irrelevant to him. Maybe they always had been. Greg was the only one that mattered, and not because William gave two shits about him. No, he was the one that listened, and in the end that was all William cared about. A fucking audience.

Yet just then, there was a hint of something else, underneath that haughty mask. Something that made Greg wonder if Sally couldn't be more wrong if she tried. Because there, right there, Greg saw a glimpse of the same thing that got him out of bed every morning. The same thing that drove Sally every day. A desire to see justice done, and done right.

'They're all connected. All of it. Bethnal and Shadwell. The disappearing drug cooks. Even the triple murder in Covent Garden that you never solved.'

'Yeah, all because you proved our suspect was –'

'Innocent?' William raised an eyebrow at Sally's outburst. 'Of that particular crime at least. Yes. And this.' He gestured to the bloody body on the floor. 'You'll need DNA to confirm it, but that's the drop-out chemist. Covent Garden bore all the marks of a vengeance killing: gang related.’

William waved a hand as he continued to explain, ‘They were murdered to wield control, or possibly to prove a point. Whichever gang did that, did this, too. Bethnal and Shadwell: one will be alive and a member of that gang. The other will be dead. It's the way it works. The way London works. You never knew it, Lestrade, but you've been working the same case ever since the day we met. And so have I.'

'Prove it.' Anderson threw his hands in the air before folding his arms and shaking his head. 'All this, you're just pulling it out of your arse. So go on, prove it.'

The look William gave him chilled the blood in Greg's veins. Not cold, because that would have required some emotion. That gaze was completely dispassionate and removed, all traces of humanity fled. William looked at them like they were nothing but tools which had caused him disappointment in their failure.

'I rather think that's your job, and as you so eloquently stated only a moment ago: you don't need my help,' he replied. 'Good luck, Inspector.'

He left without complaint, offering a thin, hollow smile to the officers who had arrived to remove him from the property. He followed their orders as docile as a lamb. It was the right thing to do, getting him out of here. He was a civilian. One with no place at a crime scene.

So why did Greg feel like he'd just kicked out the only one of them with any clue about what was going on?

Plus One

He was a dead man breathing. He'd got too close to something, caused too much trouble, and now someone was about to shut him up, permanently.

The others on the force would be looking for him. He'd have been missed when he didn't show up for work this morning. They'd have gone to his place, but there wouldn't be much for them to find. A bit of blood from a blow to the head, maybe, but the ones who took him knew what they were doing. They'd left nothing of themselves behind.

This wasn't some kids playing at being big men in the gangs. This was the big men in the gangs. The ones who killed without hesitation. The ones who ruled over chunks of the city with iron fists, commanding through fear. Maybe most people never knew they were there, working behind the scenes, exploiting all they could out of their neighbourhoods, but their anonymous fingerprints were all over everything.

He'd be a warning. Would they make it quick: a bullet to the head, execution style? Or would it be like Gareth Bates, the chemist who'd refused to sell them his product? Bludgeoned to a pulp and left like so much meat?

Greg's stomach rolled a warning, and he leaned against the cold, concrete wall. His head ached where they'd hit him, and something had happened to his ankle – broken or sprained, he couldn’t be sure. They'd lashed his arms and legs with zip ties almost all the way to his elbows and knees. He wouldn't be getting out. Not without help.

Honestly, the only surprise in all this was that they hadn't offed him already. Why not kill him in his flat and be done with it? Unless they planned to send a message not just to his team, but to the entire city? This is what happens when you mess with us. Why else would they keep him here?

He wet his lips, his breath escaping him in a shuddering rush. Tears pricked at his eyes: fear, grief, misery... He didn't want it to end like this.

A sound outside made him tense, his body rigid with rejection. Time moved on. As much as he might want to stay here, living in a bubble of uncertainty, the world didn't work like that. One way or another, this was going to end. Greg could only pray that it'd be quick and painless.

The bolts on the door slid open, and Greg shuffled back into the corner, bracing himself in the vee of the wall. There wasn't much of anything he could do, but maybe he could get in one good kick – give some arsehole a bruise to remember him by, at least for a little while. His lips pulled back, revealing the brittle slash of his snarl, and he stared, unblinking, as the door eased open, whispering on hinges that should have screamed their dirge.

Later, much later, he'd notice those details: peace when there should have been brashness, stealth when confidence had its place. He would see all the evidence he'd needed to work out who would walk over that threshold, but in that moment, he could not believe his eyes.

'William? '

'Shhh,' William urged, placing each step like a dancer floating over the stage, every movement planned as if he were walking through a minefield. He kept his body turned so he could listen, one eye on the door and one ear tilted to catch any hint that he had been discovered. 'Let's get you out of here.'

The snick of a flick knife sounded like a gunshot: blasphemy in church. The blade shone in the meek glow from the single bulb overhead, and Greg watched it slice through the coarse plastic, snapping through his bindings. William moved carefully, Greg noticed, wary of causing more injury. It would be easy for the knife to slip, and that was the last thing either of them needed.

Greg hissed as blood rushed back into his lifeless fingers and toes, stifling a whimper as his stiff shoulders protested his sudden freedom. Christ, how long had he been sitting here in the cold, waiting for death? Now, against all the odds, it seemed a guardian angel had turned up instead. 'How?' he whispered, his words little more than a shaped breath. 'How the bloody hell did you find me?'

'News travels fast,' William murmured. 'Especially if you know how to listen. I got to your flat before your minions at the Yard showed their faces.' He rolled his eyes at the concern flashing over Greg's features. 'I disturbed nothing. I didn't need to. Mud on the doormat. Ash outside. Lichen, not likely to be found in your charming little street. All of it pointed here.'

'Here being?'

'Shadwell.' William held out a hand. 'Can you stand? The sooner we get you out of here and back to the Yard, the better.'

Greg lurched to his feet, biting off a curse as his head throbbed and his ankle burned. He didn't expect the band of William's arm around his chest, supporting his weight. God, but it hurt. He felt like he'd been hit with a –

'Lead pipe,' William explained. 'I found it discarded a couple of streets away from your flat.'

'How?' Greg whimpered, knowing he was repeating himself, but it was the one query that kept rising time and again. How was this madman pulling information out of thin air like some kind of fortune teller? How was he finding answers before anyone else seemed to figure out the questions?

'Distinctive splatter from your head wound gave me the approximate size and weight. I knew what I was searching for, and I have... contacts. I knew where to look.'

'Contacts? Fucking hell, William, if you're one of them...' Greg left the threat hanging, not knowing how to finish it. After all, what could he say to the man who was his rescuer? What possible threat could he muster?

'I think not, Detective Inspector.' William huffed, apparently debating whether to continue and put Greg's mind at rest as they eased their way towards the door. 'Gangs leave a great deal of destruction in their wake. Many people suffer under their rule. They lose homes and businesses. They cluster in the shadows, and no one remembers them. Not even those who put them there.'

'The homeless?'

'They're everywhere, Lestrade, and they see everything.'

'And they tell you? Why?'

'Because I see them when the rest of the city does not.' There was an air of finality in William's voice, and Greg knew it was the best non-answer he was going to get. 'Now, hush. They want to make a performance of your execution. That's the only reason they did not do away with you in your flat. For now, they're – distracted – but it won't last forever.'

Greg nodded, not daring to ask just what this mad, brilliant bastard of a man had done. In this case, ignorance was bliss, and the less he knew for sure, the better. Plausible deniability and all that. Maybe William hadn't done anything illegal, but it definitely didn't follow procedure.

He kept his lips shut, sealed together in a tight line as he leaned on William. He steered them through a small network of narrow corridors that soon opened out onto a warehouse floor.

The building's walls were pocked with holes, great gaping wounds of decay. Greg could hear the rain drumming down on the roof, collecting to drip with gruesome intent onto the pitted concrete. One of the old industrial estates, he surmised. They were prime territory for dodgy shit: too tumbledown for anyone to look at twice. 'Mud led you here?' he hissed.

'Oil in the mud, actually. Now we –' William cut off abruptly, his long body turning to stone at Greg's side. Those eyes narrowed, and he guided Greg back into the shadows. 'Stay here.'

'Wait, what are you...?' He swore as William abandoned him, leaving him slumped against a few old metal crates. His ankle hurt like the blazes, throbbing and sick. If not for that, he'd be up and after William in a heartbeat. No way was Greg leaving him on his own to face whatever he'd heard. Even now, he considered dragging himself forward, making a fuss: something!

Before he could move, the lights came on: distant, pendulous bulbs flickering into life amidst the rust-pocked rafters. There was no time to wonder why the place still had power. His shield of shadows had weakened, though a pool of gloom offered him a sliver of protection.

The same could not be said for William.

He stood like a prima donna in the spotlight, his chin held high and that black coat spilling from his shoulders. He commanded attention with his mere presence, every angle of his body screaming in arrogant challenge. Part of that was his natural stance, but Greg knew him a bit better than that, by now.

William knew how to show you what you wanted to see and play to those assumptions. Hell, he'd probably been doing it to Greg since day one. Now, he held his audience captive: four men of indeterminate age, somewhere between twenty and thirty, all wearing the colours of the Kingshold Boys and staring at him in baffled disbelief.

'Who the fuck are you?' one demanded, strutting forward with his chin stuck out like some prancing peacock. A runt with something to prove, Greg thought. Dangerous, those ones, for all that they were thick as shit. Their position in a gang was tenuous at best. Easily disposed of and easily replaced.

The other three said nothing as they exchanged quick, dark looks, hands slipping into pockets. They reached for knives, not guns. Firearms were hard to come by in the UK, even to those with ties to the criminal underworld. Besides, the Kingshold Boys took it as a matter of pride. They killed up close and personal, not with a bullet. 'What the fuck you doin' here?'

William raised an eyebrow. 'Sightseeing,' he replied, flat-voiced and indifferent.

'He thinks he's a joker! Rich toff on the wrong side of town,' the cocky one crowed, pulling a blade from his belt. It was no little pocket-knife, two handspans long with ease. The young yob tossed it in the air, sending it spinning in a practiced effort, a shark-like grin locked on his lips. Greg watched it go, flashing silver beneath the lights as terror rushed in icy waves down his spine.

A cry of alarm: a thud. Greg blinked and stared. Four were now three, and the hand holding the weapon was not the scarred, knobbly mess of the young thug, but William's. Deft fingers caught the hilt with practiced grace. Everyone else had been watching the weapon. He'd been watching its would-be-wielder, who now lay at the feet of his gang-brothers in a crumpled heap, unconscious.

'Bloody hell,' Greg mouthed to himself, feeling the air in the room pull taut. It was the precipice of a moment, where the world could tip either way. A heartbeat later, the frozen tableau shattered into a flurry of action.

The three remaining gang members lunged at William. One had a knife, the other two had brutal brass rings over their fingers: knuckle-dusters adding their bite to every blow. They moved with the kind of ragged brutality that a kid learned on the streets, all tumbling speed and unchecked strength.

They rushed William without a second-thought, never stopping to wonder why the man before them neither flinched nor fled. He met them with his head held high, his expression locked in an apathetic mask of intense concentration.

Greg's heart lurched in his throat. William had got lucky, but three against one were no fair odds. Worse, there was nothing he could do about it. His throbbing ankle wouldn't let him stand. He could barely even crawl!

His voice lay trapped somewhere beneath his Adam's apple. Never, in all his life, had he felt so helpless. All he could do was watch, and he would. He'd bear witness, on the slim chance that he got out of this in one piece. He'd get William justice. He'd point them out of a line-up and lock 'em up for good.

A swirl of black wool obscured the vision of the one on the left. William ducked beneath his blow and weave away from the other on the right, heading for the knife-wielder as if the other two were nothing but an inconvenience.

They saw it coming, of course they did, but his swift, graceful step meant he was a fraction of a second ahead, his arm braced across his own body, lashing out with phenomenal force. The backhand caught the knife-wielder in the throat. He made an awful noise: a gagging retch like William had just slit him open, but no blood spattered onto the floor. Instead, he doubled over, the scar on his face puckering as he wheezed for air.

The sole of William's shoe slammed into his face a moment later, and Greg almost felt sorry for him as he went down like a tree, his face smashed and his lips slack. There was no time to celebrate a second victory. Before Greg could even draw breath to shout a warning, a brass-bound fist caught William squarely in the mouth, sending him flying.

Anyone else would stay down, give their rattled senses a chance to settle, but William was already rolling, springing back to his feet as he claimed the momentum for his own. Crimson dripped from his lips and teeth. It dribbled down his chin to smatter his coat and shirt, but he made no effort to cuff it away. There was no bravado or witty repartee, he merely cocked his head, his mercurial gaze raking over the two that remained like a predator sizing up its prey.

The two gang members that remained looked older. One had a shaved head, gleaming white in the warehouse lights. The other had his hair pulled back in a stumpy ponytail, the slash of his grin marred by a missing front tooth.

Both of them watched William with the practiced air of fighters looking for the upper hand. They never stopped moving, always circling, searching for a weakness, but William never let one of them get behind him. He stepped in perfect counterpoint, keeping himself at the peak of a triangle as he led them, step-by-step, away from Greg.

Who blinked first, Greg couldn't say. All he knew was that, between one breath and the next, the two lunged for William, fists driving forward in practised unison. He twisted, but one still caught him a glancing blow to the ribs, hard enough to break bone. Greg's lungs clenched in sympathy, his heart thrumming as a second punch caught William in the belly, bending him double.

The next moment, he snapped upright, just as one of them approached to finish him off from behind. The back of his head collided with the bald one's chin, the crack echoing around them. William reached behind him and grabbed at his attacker, hauling him forward to sprawl on the ground before slamming his foot into the hollow of that shaven temple.

Greg almost whooped for the joy of it. They were down to just one, now. The prick with the ponytail stayed back, his brown eyes nothing but slits as he surveyed the fallen forms of his brethren. William's chest heaved, the blood still welling from his mouth, but his gaze held that same, intense focus as always.

His knuckles were scraped all to hell, but not once had he needed to use the knife's blade. He'd risked cutting his own palm to ribbons, relying on the hilt to give his blows that little bit more weight. Now, he sized up the last one before lifting his chin, jerking his head towards the door. 'Tell Pritchard that Globetown Massive send their regards.’

'You're with them?' Ponytail asked, sounding, for the first time, as if he wasn't sure this whole mess would go in his favour.

'The copper was theirs before he was yours. You’re the ones who started this.' William lifted one shoulder in a shrug, though it must have hurt like the blazes to do it. 'You want to make a war of this?' he demanded, preying on the knowledge of how closely gangs guarded territory and targets alike. It took Greg's breath away, and not for the first time, he thanked any god that listened that William was on their side.

'Nah, nah.' The one with the ponytail held up his hands, palms out and fingers spread in an effort to appease. His eyes darted around as if he were looking for William's backup, some additional numbers that could explain the confidence of the man who stood, bloody and beaten and bold as brass in front of him. 'That's not my call.'

'Obviously. I suggest you run back to whoever's in charge. Consider yourself the messenger, and hope he doesn't shoot you.'

Outside, the sudden scream of sirens ricocheted through the air. The man with the ponytail flinched, but William did not bat an eye. A cruel smile twisted his bloody mouth, his eyes falling flat and lethal. 'Now.'

Greg had never seen someone move so fast in his life. The last thug standing took off like a greyhound from the starting gate, haring off into the shadows in an effort to flee the scene.

William remained motionless just long enough to watch him go. The next minute, he too leapt into action. Grabbing the wrist of one of the unconscious ones, he wrapped his limp hand around the hilt of the knife, leaving it cradled in his grasp. Stumbling, he checked his surroundings, scanning the floor for God-knew what before he hurried back to Greg's side.

'It's Donovan and the others. When they ask, you had this and were able to get yourself free.' He pressed the small flick-knife he'd used to cut Greg loose of his restraints into Greg's palm. 'You dragged yourself out here to find them like this: fighting over who would get the right to take you out. There were only ever three.'

'What?'

'You'll have to trust me on the rest. If the Yard starts hounding the gangs now, it's only going to get worse for you. If you're lucky you’ll end up in witness protection and all that rubbish. At worst you'll be dead in an alley within the week. The gangs don't stop. They won't give up. Not without some terminal encouragement.'

'You can't kill them,' Greg argued, shaking his head. 'Fuck whether it's legal or not. There's one of you and God knows how many of them.'

'Don't be dramatic,' William chided, taking one last look around as if analysing the scene. 'I will do nothing of the sort. Give it five days. Make sure you're safe. It should be over by then.'

'What about you?'

William's wrecked mouth twisted in a smile. It had to hurt, but there was a gleam of something like amused triumph in his eyes. 'I'll be in touch.'

Greg's squawk of protest fell on deaf ears as William turned away, all but melting into the gloom. He strode deeper into the warehouse, heading for another way out just as a platoon of cars screamed to a halt at the main entrance.

Greg let his head fall back, mouthing exhausted curses at the ceiling as chaos descended. Sally was the first to reach his side, her concern genuine and deeply gratifying. He was tempted to tell her all of it, bugger what William wanted, but at the last moment something choked the words in his throat. He wet his lips and tried to smile, pretending his winces were all about the pain as he spun William's little lies with as much skill as he could muster.

Five days later, news began to trickle through. It carried on the whispers of the bobbies on the beat and came rushing in from the morgues as the bodies arrived. Gang warfare, not among the cannon fodder as was so often the case, but between the top dogs.

The leaders of Globe Town Massive, the Kinghold Boys and the Pembury Boys all lay on mortuary slabs. Their lieutenants followed soon after. The gangs tore themselves apart from within, fighting tooth and nail until there was nothing left. Those few that survived drifted off into London's shadows, lost forever, and what could have been the beginning of the end for Greg became just another day on the job.

What William had done to bring it about, he couldn't say. He sat at his desk reading yet another report on the whole sorry mess. The Yard took the credit, of course, even though all they'd done was stir the pot to boiling point. Still, London's streets were that little bit safer, at least for now, and Greg could get on with his life. No worrying about a gang doing him in when they got the chance.

The buzz of his phone caught his attention, and he dragged the Nokia out from his pocket. Scuffed and beaten, it had survived his days on the job with grace. Now, a message from an unknown number awaited him. A tap of a button brought it up on screen. Greg's breath stilled in his throat as he read the short missive.

"The name is Sherlock Holmes. Consulting Detective. Let me know when you have any cases worth my time -SH (William)"

A smile curved Greg's lips, baring his teeth in a grin as a bubble of laughter hitched in his chest.

'Sherlock Holmes,' he repeated to himself, savouring the taste of it in his mouth. It sounded stuck and pretentious, more made up than "William" had ever been. Yet it was the truth: he knew that down in his bones.

Being a copper was a hard life, full of cases that never got anywhere and thankless insights into the very worst humanity had to offer. Now, change was in the air. Greg could almost smell it. All thanks to this man, this consulting detective, as he called himself.

This "Sherlock Holmes".