Chapter Text
“Keep going. I’ll hold them off.” Alec said, raising his bow and pointing it down the hallway.
“What are you talking about? If you’re staying, then so am I.” Jace drew out a seraph blade.
“You need to make sure that the Cup gets back to the Institute. Clary won’t make it without you. You’re wasting time.” Alec said flatly, shooting down the single shax demon that had already found them.
“Jace, go.” Isabelle said. “Getting Clary and the Cup back to the Institute is what’s most important. I’ll stay with Alec.”
Alec looked at her imploringly. “Izzy—”
“Alec, shut up. Jace, Clary, leave. We’ve got this.”
The blond shot his parabatai a last desperate look before ushering Clary away. As their footsteps faded into the distance, Isabelle gripped her whip and blade in either hand.
“You should go with them.” Alec said, not taking his eyes off the hall before them as they heard more demons approaching.
“And leave you to have all the fun?” Isabelle said, throwing him a smile. When Alec opened his mouth to speak again, she cut him off. “There are too many of them after the Cup. You’ll die if you fight alone, and I’m not letting that happen. I love you.” She said firmly as the first demons came scuttling into view.
“I love you too.” Alec said quietly before he started firing off arrows into the fray approaching them.
As Shadowhunters, they were used to dispensing of the occasional demon or rogue downworlder. Several at a time even, when they were all together. But they were still young, and even the most experienced Shadowhunter would have a difficult time against the sheer multitude that rushed at the siblings. They took down dozens before they were surrounded and exhausted, Alec out of arrows and forced to use blades instead.
Isabelle let out a small cry as one got past her defenses and clawed at her arm, tearing the skin and drawing blood.
“Izzy!” Alec quickly killed the creature and tried to place his sister behind him, but they were nearly surrounded on all sides.
“I’ll be okay.” She forced out through gritted teeth, keeping her injured arm close to her side. “It wasn’t a bite.”
The fight carried on for several more minutes, the number of demons dwindling until finally, Alec plunged his seraph blade into the last one.
Isabelle let out a relieved sigh and dropped to her knees. After looking around them for more threats, Alec crouched beside her and gently took her arm, drawing an iratze on it. “Are you okay?” he murmured.
She nodded, smiling up at him before her eyes widened. “Alec!”
He turned, only to see Forsaken warriors coming at them down the corridor. He leapt to his feet, darting around to grab up the arrows that had fallen to the ground when the demons vanished as they died. He quickly nocked one and fired, felling the first before pulling Isabelle back to her feet. “They have to have made it back by now. We need to try to get back to the Institute.”
Isabelle nodded, looking warily at the rapidly approaching hoard. “Let’s go.” As she turned to run, she was faced with two more that had come in a different way. She stabbed the first as Alec lunged forward and did the same to the other. By then, the rest had caught up behind them. Isabelle turned to Alec fearfully. He glanced back, a grim expression on his face. Seeing her fear, he tried to muster a reassuring smile before he fired off his arrows for a second time, noticeably trying to get the ones that were closest to his sister first.
Forsaken warriors were much harder to kill than shax demons, though. Most could not be felled by a single stroke or arrow, and so they closed in much faster than the demons had. They were more brutal as well. As soon as one got close enough, it swung a cudgel-like weapon into Alec’s leg, shattering the bones on impact and sending him to the floor as he was unable to contain a yell at the sudden and intense pain.
“Alec!” Isabelle screamed, quickly moving to stand over him. She killed the warrior that had attacked him before another came up behind her. Alec dragged himself into its way before its blow could hurt her, but it caught him in the shoulder and sent him flat on his back, unable to breathe for several moments. He reached shakily for his bow, knowing that he would not be able to stand in order to fight anymore. Isabelle managed to hold her own for a while, but then a single swing caught her in the back and she fell to the ground beside Alec, unconscious.
Expecting to be killed, Alec tried to make a final stand to protect his sister. Just as the Forsaken got close enough to finish them off, they suddenly stopped moving and then backed away. Alec dragged himself so he was shielding Isabelle before looking up at what caused them to stop their approach. His stomach dropped as he saw Valentine himself walking into the room, clapping slowly.
“That was quite the fight. I’m actually impressed.” He said with a sarcastic lilt. Alec flung his seraph blade at the man, but he ducked out of the way before it could hit him. “It’s so rare these days to see any actually good Nephilim. It’s refreshing.” He chuckled, coming to a halt several feet from the two. He motioned to the Forsaken, and then two grabbed Alec’s arms and hauled him to his feet, his leg screaming in protest. Another took Isabelle and threw her over its shoulder. Alec tried to stare defiantly back at the man, but the impact was somewhat lessened by his pallor from the pain. “Perhaps now Maryse will be more open to negotiating with me. The Mortal Cup in exchange for her children? I think that’s fair, don’t you?”
“The Clave will not negotiate with you.” Alec spat, struggling to stay upright on his uninjured leg.
“The Clave doesn’t need to. I just need Maryse or Robert to go on one little rogue mission to save their beloved children.” Valentine smirked before looking just past Alec. “Knock him out. Bring them with us.” A moment later, Alec felt a burst of pain in his head, and then nothing.
-----
“They should be back by now.” Jace said, pacing in front of the screen at the Institute. “We should look for them. Gather a team—”
“Jace,” Clary put a hand on his arm. “I’m sure they’re okay. They probably just didn’t want to lead anything back here, right?”
He visibly tried to consider this notion before shaking his head. “No. Maybe I could believe that if they were just a short while behind us, but over two hours? Something went wrong. One of them got hurt, or both, or—” His gaze shot up as Maryse walked quickly out of a conference room, calling sharply for her husband. “Maryse!”
“Not now, Jace,” she cut him off without looking at him and then shut a door behind her.
“Something is definitely wrong.” He turned to the screen and began typing. “There had to be security cameras in there somewhere, right?” he muttered absently.
“Jace, I don’t think—”
“There.” He stood back as the grainy black and white video was brought up on the screen. He sped through the footage until the group entered and then let it play. He grimaced as Isabelle was hurt, and Clary watched in horror. “They handled the demons. Why then aren’t they back—?” The Forsaken came within view of the camera. Then Alec’s leg was shattered by the Forsaken, and Jace let out an almost silent gasp of fear before his parabatai was hurt again, and then Isabelle was knocked unconscious and Valentine entered, his back to the camera.
This time it was Clary who gasped. “That’s Valentine. Oh my God.”
Jace’s expression was blank as he watched the screen until the two Lightwoods were carried out of sight.
“Jace?” Clary stepped forward, eyeing him worriedly with tears in her eyes. “He… he took them. So they’re still alive. Right? Jace.”
He was silent and still for several more moments before he leapt into action, sprinting to the room Maryse had entered and bursting inside. “You know, don’t you?” he demanded, Clary running after him to stop in the doorway. “He has them. Valentine has them.”
Maryse and Robert looked at him, both with red-rimmed eyes.
“He wants the Cup, Jace. We… we can’t do that.” Robert said brokenly. “Giving Valentine the Mortal Cup would be guaranteeing their deaths anyway, along with that of the world. We just… We can’t.”
Jace looked stunned. He could never have expected that they would just give up. “But… But Alec. Izzy.” He shook his head, uncomprehending. “We can’t just leave them. He’ll kill them.”
“You think we want to?” Maryse demanded, turning her tear-streaked face to them. “This is… the most abominable thing I will ever do. And I will never forgive myself. But we… We are Shadowhunters. Sacrifice is expected. They know that. I know that.” Her voice wavered and broke as she spoke the words meant to convince herself as much as Jace.
“Okay.” Jace shook his head. “I know we can’t give him the Cup. But we can track them. We can fight to get them back. I’m not letting them die.”
-----
“Hello, Alexander.”
Alec slowly forced his eyes open, trying to ignore the splitting pain in his head. He was met with the sight of a cage around him before he even realized that his hands were chained above his head, his toes just barely brushing the ground. He tried to move, but excruciating pain flared up his leg and shoulder and he barely kept from crying out. He looked around desperately, seeing Isabelle in a similar situation a few feet away inside a separate cell before Valentine stepped up and blocked his view of her.
“Isabelle, too. Time to get up.” He called.
Very slowly, Isabelle regained consciousness, grimacing in pain before opening her eyes. They filled with fear when she saw Valentine, but she did not speak. She looked past him to Alec, her gaze filled with pain and worry.
“Good, everyone’s awake.” Valentine smirked. “Now, while we wait for your parents to debate how much your lives are worth to them, I thought you could help me test something out.” He leaned casually against the bars of Alec’s cell and lifted a syringe filled with a black, viscous liquid. “You see, I’ve enjoyed experimenting with demon blood for many years. Something I never tried, though, was demon venom.” He flicked the needle. “Because, you know, it kills you. But I’m curious about how long that takes for certain doses and different species of venoms. A bite from a ravener demon may kill you slower than that of a behemoth demon, but is that just because it draws less blood or because the venom is less potent?” He leaned forward, smirking at Alec. “I’m curious to find out.”
With that, he reached through the bars and stuck the syringe into Alec’s neck, pushing down the depressor as Isabelle screamed weakly for her brother. Alec groaned in pain, and black veins immediately spread from the injection point.
“Let’s see how long you manage to last. Now, for you.” He turned and walked over to Isabelle, drawing out a second syringe. “You’re so small that I figured I’d give you a lesser… dose. Just to give you a fighting chance, I suppose. If I’ve figured this correctly, you should live a good hour or two longer than your brother.” He smiled cruelly as he injected Isabelle as well, to the sound of both siblings’ protesting cries. “I’ll let you know if your parents decide they care to save you.” He said before walking out of the room.
“Izzy,” Alec croaked, tugging at the chains. “Izzy, are you…?”
“We’ll get out of this, big brother,” Isabelle said tearfully, still trying to muster a smile. “Come on, we’ve been through worse, right?” The weak smile turned into a grimace.
“I think this might be the winner, actually.” Alec tried again to break from the chains, but a new pain flared from the spreading venom.
“Don’t be such a downer,” Isabelle panted, trying to kick out her cell door and wincing with every movement. After several minutes, she stopped moving, gasping for breath. The venom was spreading too quickly.
“I wish you hadn’t stayed.” Alec murmured, already feeling weaker. “I’m so sorry, Izzy.”
“Hey,” she reprimanded him. “It was my choice. I’m never going to leave you.”
“I know that.” He smiled weakly at her. “And I love you for it. I just wish… that you never had to get hurt. I’m so sorry I couldn’t protect you.”
“Alec, it wasn’t your fault. I’m shocked that we survived even the demons. There was nothing you or anyone could’ve done against so many Forsaken. Besides, I couldn’t protect you either.”
“You did your best.”
“So did you.” She glared at him for a moment before her expression fell almost to despair. “What do you think they’ll do?”
“Mom and dad?” Isabelle nodded. “They’ll want to come.” He felt it get more difficult to breathe as the venom spread towards his lungs. “But they won’t trade the Cup. And they shouldn’t.”
Isabelle sadly nodded her agreement. “Do you think they’ll try to find us anyway?” she asked in a small voice, sounding so much younger than she was.
“Of course,” Alec tried to soothe her. “They’re not just going to give up.”
“Then we can’t either.” She said definitively. “Stay still. Stay quiet. Try to stop the venom from spreading. We’ll give them as long as we can to get to us.”
“Izzy—”
“That’s our only option, Alec. We won’t get out of here on our own, so we have to rely on them coming to get us, and that won’t matter if we’re dead from trying to kick the walls down and speeding up the process of the venom. Just don’t move and don’t talk, and maybe we’ll live. And if not…” she swallowed harshly, tearfully meeting Alec’s gaze. “If not, then just know that I love you more than anything and I’m sorry.”
Tears fell from Alec’s eyes as well as he stared back at his sister. “I love you too, Iz. So much. I am so, so sorry.”
She nodded mournfully, holding his gaze as they both went silent and still and tried to live long enough to be rescued.
-----
“They’re close.” Robert said, looking around the location they had tracked Alec and Isabelle to. Maryse glanced at the buildings around them, drawing out a seraph blade.
“He’d want to be somewhere well-protected. As close as possible to the water, to disrupt tracking attempts. That building,” she pointed, “seems most likely.”
“I agree.” Robert said, lifting his own blade. Jace and Clary followed behind them. “If we encounter Valentine, only Maryse and I will engage with him. You two try to get Alec and Isabelle out of here. If it seems like we won’t be able to follow, go anyway. Do you understand?”
Jace looked conflicted as he nodded, his eyebrows furrowed in pain as he rubbed at his parabatai rune. Robert noticed, and he closed his eyes for a moment, taking a deep breath to calm himself.
“Everyone stay quiet. If we give any warning that we’re here without the Cup, he could kill them.” Maryse instructed. The rest filed into a narrow hallway after her, weapons ready to strike. At the end, it branched into two corridors, and the group split in half.
Jace and Clary traveled for another minute before they entered a great room filled with cells. Seconds later, Jace gasped as he spotted Alec and then sprinted to him. Seeing Jace working to pry open the door to Alec’s cell, Clary ran to do the same for Isabelle.
The metal clanged as Jace finally got it open, and the noise caused Isabelle to blearily open her eyes.
“Clary?” she said weakly.
“Izzy!” Jace called quietly, now struggling with Alec’s chained wrists.
“It’s okay, we’ll get you out.” Clary promised.
Isabelle closed her eyes again, a tear falling from one. “Alec…”
“He’ll be okay. You both will.”
“He stopped… answering me…”
“He’s alive, Izzy.” Jace said, voice wavering. He detached the chains and caught Alec as he fell limply. “I would’ve felt it if he…” he shook his head and lowered Alec to the ground, drawing an iratze on him before sprinting to Isabelle and getting her door open. He yanked at the chains until they broke and caught her in a hug. “Can you walk?”
She tried to take a step but fell against him.
“It’s okay. It’s alright, Izzy.” He quickly traced over her iratze as well. “Clary, can you help her? We need to get back to the car.” He waited for Clary to nod before running back to Alec and pulling him into his arms. “Come on.”
Alec’s breath was weak and labored. Jace could barely hear it anymore. He knew Isabelle wasn’t in much better shape either. When they got outside, they were met with Robert and Maryse fighting against three of the Forsaken. When they saw their children, they quickly dispatched of the creatures and ran to them, helping them into the car. Robert drew another iratze on Isabelle while Maryse did the same for Alec.
“Thank the angel,” Robert said as Maryse began to speed them back to the Institute. “I thought…”
“Daddy?” Isabelle’s voice was hoarse as she spoke.
“It’s okay, Izzy. You’re safe now. I’m so sorry for all of this, but it’s over now.”
“No,” she leaned into Jace, who was between her and Alec. “No, Valentine… he used demon venom on us. The iratzes won’t heal it…” she said weakly. “Alec stopped answering me.” She said again, tears filling her eyes as she tried desperately to reach her brother while the venom hindered her movements.
Maryse’s expression tightened in fear. “We’ll need a warlock, then. Fast.”
“Magnus Bane,” Clary said quickly, her own eyes filled with tears. She held onto Isabelle’s arm. “He healed Luke. He can help them.”
“We have to try.” Robert said. Time seemed to pass too quickly as they raced to the warlock’s apartment, Clary giving directions. By the time they reached it, Alec’s pulse was dangerously slow and his weak breaths were tiny wheezes that barely allowed him any air, and Isabelle was barely conscious. They stopped abruptly, Clary running ahead as Robert lifted Alec and Jace carried Isabelle.
Clary pounded on the door, hoping desperately that Magnus would be home and not out somewhere at three in the morning. The door flew open after a minute to reveal Magnus, who had clearly been asleep.
“Clary Fairchild,” he said unhappily. “You know, I know you’re new to all of this, but warlocks do need to sleep, especially after exerting—”
“Magnus, thank God.” Clary interrupted. “We need your help.” Her voice broke.
Magnus’ eyebrows drew together in concern. “Luke should be fine—”
“No, it’s Isabelle and Alec.”
His lips pressed into a tight line. “Where are they?”
“Robert, Jace, and Maryse should be bringing them up now.” She said quickly. “You have to save them.”
Magnus left the door open and went back into the apartment, clearing the couch he had healed Luke on just the previous night. “What exactly happened?” he demanded.
“There were demons. Alec told us to go ahead and that he’d hold them off but then Isabelle stayed. They killed all of the demons, but then there were Forsaken warriors and they both got really hurt and then Valentine took them and he apparently used demon venom on them. Alec’s almost dead.” She whispered tearfully.
Magnus nodded, jaw clenched. “I’m going to need to draw on all of your strength. My magic is still almost depleted from yesterday.”
“But that won’t work with all of us,” Clary said mournfully.
“What? Oh, no, I can use any of your Shadowhunter energies. It’ll work fine—”
He stopped speaking as Jace came into view with Isabelle cradled against his chest.
“Set her down here. Clary, put your hands on my shoulders.” Magnus said, holding out a hand over Isabelle’s neck where the venom had been injected. His face screwed up in concentration for several moments as a blue glow poured from his hands into Isabelle’s body. Robert entered the apartment moments later with Alec, and Magnus paled at the sight of him. “Next room. Bed.” He said through gritted teeth, jerking his head in the direction Robert should go. Maryse appeared and followed him several seconds later. Magnus continued pouring his magic into Isabelle for the next several minutes before breaking off. “She didn’t have too much in her system, and it must’ve been a lower one of the lesser demons as well. An iratze will tide her over now. You, with me.” He said, looking desperately worried as he ran to the bedroom.
“Isabelle?” Maryse demanded.
“Doing better than Alec,” Magnus said, getting on the edge of the bed and leaning over Alec’s prone form as Maryse left to see Isabelle. “Blondie, I need your strength.” He said, pressing a hand to Alec’s chest and placing the other on his neck. He squeezed his eyes closed as he focused on locating the demon energies and pulling them out of the boy. “Come on, Alexander.” He muttered, feeling the weak heartbeat that gave a barely fluttering pulse in his neck. He felt another hand join Jace’s, and he began to draw from Robert as well.
Ages seemed to pass as the warlock channeled everything he had into saving Alec’s life. Curse this boy for getting under his skin after he had successfully navigated a century without having his heart broken. He barely knew him before they stayed up talking the entire previous night, and yet he had already become utterly irreplaceable to him. If he failed him now and let him die before they even had a chance… he would be closed off for the rest of his life. He would not be able to love again. ‘Stupid Shadowhunters, always having to be selfless and getting themselves killed.’
When Magnus next looked up from the most important task of his life, the sun was rising and while he felt terribly weak after nearly three straight hours of healing, he could feel Alec getting stronger. He hadn’t even realized that Maryse and Clary had ended up helping as well until he broke away from them all at last, folding down against Alec’s chest and panting for breath. He knew that Alec still had other injuries, but the venom that seemed to have come from a greater demon was now out of his body. He would live.
“Will he be alright?” Maryse spoke from behind him, and he forced himself to sit back up. He turned shakily to face the woman.
“He should be. He’s still wounded, but I got all of the venom out, so it’s not life-threatening anymore.” He glanced back down at Alec, whose skin was frighteningly pale and damp with sweat. “I need to check on Isabelle,” he said, as much to convince himself to leave as to alert the others. He got to his feet very unsteadily and slowly made his way back into the other room. A quick scan of the girl’s body revealed that he had been right initially and that she would be fine. He let out an exhausted sigh and then worked his way back to his bedroom. “Isabelle will be alright to return to the Institute, but I want to keep Alec here until I can finish healing him.”
“Can’t you finish now?” Jace’s voice would’ve sounded demanding if it wasn’t laced with almost the same exhaustion and barely assuaged fear that Magnus felt.
“I need to rest. I have to replenish my magic. Even with drawing on someone else’s strength I wouldn’t be able to do anything more now. This would have been impossible enough without having given everything to Luke yesterday.”
“We understand,” Robert said. “And I cannot tell you how much we appreciate this. I owe you the lives of two of my children.”
“But,” Maryse cut in, eyes still red from crying. “I want to take him back to the Institute. I won’t leave him here.”
“I assure you, he’s well protected. My loft may even be better warded than the Institute. He just shouldn’t be moved at all in this state.”
Robert and Maryse exchanged a long look before Maryse sighed in defeat. She walked around the bed and pressed a kiss to Alec’s forehead, smoothing back his hair and cupping his cheek before quickly turning away and walking out of the room without looking back. Robert did much the same, except he thanked Magnus again on his way out. Clary followed them after squeezing Jace’s arm reassuringly and throwing Alec a final glance.
Jace stood over his parabatai for a long moment before picking up his hand and holding it to his chest. “Don’t you dare ever leave me.” He murmured, eyes pained as he stared down at the unconscious boy. “Don’t you even think of it, Alec Lightwood.”
Magnus went out and leaned on the wall next to the doorway, waiting for the others to get Isabelle and leave. It took a few minutes, but then the door closed behind them and he finally had a semblance of peace. He retreated back to his bedroom and laid down beside Alec, staring at the dark-haired boy through half-lidded eyes. He used the smallest bit of magic to bind Alec’s leg until it could be healed before collapsing back on the pillows. “You are causing me a lot of trouble, Alexander,” he murmured, settling down atop the blankets and ignoring the stray flecks of blood. He moved just enough so that his fingers were pressed against Alec’s arm before finally closing his eyes, succumbing to exhaustion and falling asleep immediately.