Chapter Text
The moment Gregory House stepped off the plane in London, he regretted every decision that had led him there. The weather was miserable, the airport was crowded, and worst of all, he was attending a medical conference. He limped through Heathrow Airport, his cane striking the polished floor in uneven rhythms, while James Wilson followed a few steps behind, dragging both their luggage and what remained of his patience.
"You know," Wilson said, adjusting his grip on a suitcase, "most people are at least slightly excited when they're invited to speak internationally."
"Most people think conferences accomplish things."
"They do."
"They accomplish free coffee and PowerPoint addiction."
Wilson sighed. They had been in London for less than twenty minutes, and House was already insufferable—a personal record.
"You could at least pretend to be grateful."
House stopped walking so abruptly that Wilson nearly walked into him. He turned slowly.
"Wilson."
"What?"
"If I fake a medical emergency right now, how quickly do you think we can get back on a plane?"
"No."
"What if it's a convincing emergency?"
"No."
"What if I stop taking my Vicodin?"
Wilson stared at him. House grinned, and Wilson hated that grin. It was usually a warning sign.
Eventually, they continued toward baggage claim, House wearing an expression that suggested he would rather be having surgery without anesthesia.
Across the city, another man was equally annoyed. Sherlock Holmes sat in the back of a taxi, staring blankly out the window as London passed by, with John Watson seated beside him. Unlike House, Sherlock was not attending the conference against his will—he simply hated public speaking. Unfortunately, solving impossible crimes had made him moderately famous, and people kept inviting him to events.
"You could try looking less miserable," Watson suggested.
Sherlock did not move. "I am looking exactly as miserable as I feel."
"Thousands of people would love the opportunity to attend an international conference."
"Thousands of people are idiots."
Watson nodded. Fair point.
The taxi continued through the city as Sherlock glanced down at his phone: three unsolved cases, one potential serial killer, and two suspicious disappearances. Instead of working on any of them, he was expected to discuss deductive reasoning with academics. The thought alone was painful.
"This will be good for you."
"No."
"You haven't left a crime scene in three days."
"No."
"You need sunlight."
"No."
Watson sighed. Sometimes speaking with Sherlock felt like arguing with a particularly intelligent wall.
The conference was being held inside one of London’s largest convention centers, filled with doctors, researchers, scientists, investigators, forensic specialists, and academics from dozens of countries. The atmosphere buzzed with excitement. House hated it immediately. The moment he entered, he spotted a group of doctors eagerly discussing diagnostic methodology—and immediately changed direction.
Wilson grabbed his sleeve. "Oh no."
"What?"
"I know that look."
"What look?"
"The look you get before causing problems."
House smiled. Wilson groaned.
By noon, House had already insulted three department heads, one Nobel Prize nominee, two researchers, and an entire pharmaceutical company. The day was progressing beautifully. Wilson was considering murder.
Meanwhile, Sherlock was having an equally productive morning. He had corrected a forensic expert halfway through a presentation, embarrassed another speaker during a Q&A session, and somehow managed to start an argument between three criminologists. Watson was also considering murder.
The collision course became unavoidable during the afternoon keynote session. The presentation involved a difficult medical mystery: a patient suffering from a bizarre combination of neurological symptoms, respiratory complications, and sudden organ failure. The speaker had spent nearly forty minutes explaining the case. The audience listened attentively.
House did not.
He sat slouched in his chair near the back of the room, Wilson beside him, looking bored—because he was.
"As you can see," the speaker continued, clicking to another slide, "despite extensive testing, the underlying diagnosis remained elusive—"
"It was fungal."
The room froze. Every head turned. House didn’t look particularly interested.
"Excuse me?" the speaker asked.
House pointed lazily toward the screen. "Environmental exposure. Symptoms started after the move. Respiratory issues came first. Everything else followed. Fungal infection."
Silence filled the room. The speaker opened his mouth, closed it, then opened it again.
"It wasn't fungal."
The voice came from the opposite side of the auditorium. Everyone turned. Sherlock Holmes stood near an aisle, hands in his coat pockets, expression unreadable.
"It was heavy metal poisoning."
Now everyone looked confused—including House. The speaker looked like he wanted to evaporate.
Sherlock continued calmly. "The respiratory symptoms were unrelated. Coincidental. The neurological presentation occurred first. You've simply organized the timeline incorrectly."
House narrowed his eyes. Interesting.
Sherlock narrowed his eyes. Also interesting.
The speaker stared helplessly between them.
"Wrong," House said.
"No," Sherlock replied immediately.
"Yes."
"No."
"You're ignoring the environmental trigger."
"You're assuming causation from correlation."
"You're assuming competence from the presenter."
A few audience members laughed. The presenter looked offended. Wilson buried his face in his hands while Watson considered fleeing the building.
For several seconds, the two men simply stared at one another. The room disappeared. The audience disappeared. Everything faded except the strange, unsettling recognition between them—not familiarity, but something dangerously close. The same posture. The same detached expression. The same irritating certainty. It was like looking into a distorted mirror.
Neither liked it.
Sherlock spoke first. "Doctor Gregory House."
House raised an eyebrow. "Consulting detective Sherlock Holmes."
The audience leaned forward collectively. This was far more interesting than the conference.
"You looked me up."
Sherlock shrugged. "You interrupted the lecture."
"So did you."
"Only because you were wrong."
House smiled, and it was not a friendly expression. "Adorable."
Watson immediately recognized that look—Sherlock wore it whenever he encountered a real challenge. Wilson leaned toward House.
"I know that look."
"What look?"
"The one you get when you've found a new obsession."
House snorted. "No."
"You absolutely have."
"No."
"You're smiling."
"I'm not."
"You are."
House hated when Wilson was right—mostly because it happened far too often.
Across the room, Watson was having a similar conversation.
"You need to stop."
"Stop what?" Sherlock asked without looking away from House.
"Whatever you're planning."
"I'm not planning anything."
"You are absolutely planning something."
Sherlock remained silent. Watson groaned. That was confirmation.
The speaker finally attempted to regain control. "Perhaps we should continue the presentation—"
"No," House said.
"Agreed," Sherlock added.
The speaker blinked in confusion.
House pointed toward Sherlock. "Now I want to hear why he's wrong."
Sherlock pointed back. "And I want to hear why he's wrong."
The audience erupted into laughter. The presentation was effectively over.
For the next twenty minutes, the two men dismantled the case from opposite directions—arguing, analyzing, interrupting, correcting, and competing, neither willing to concede even an inch. By the end, they had uncovered flaws the original medical team had completely missed. The speaker looked exhausted. The audience was thrilled.
Wilson wanted a drink.
Watson wanted two.
Eventually, the session ended. People began to leave, conversations bursting to life throughout the auditorium. House slowly rose from his seat. Sherlock did the same.
For a brief moment, their eyes met again across the room.
Neither spoke. Neither smiled. Neither looked away.
A challenge had been issued. Neither knew exactly what it was—only that it existed, and neither intended to lose.
As House turned toward the exit and disappeared into the crowd, Sherlock continued watching. Watson stepped beside him.
"Don't."
"Don't what?"
"Whatever you're thinking."
Sherlock remained silent.
Watson sighed. The silence was worse—much worse. Because Sherlock Holmes had just encountered something he had not found in a very long time.
A mystery.
And Gregory House had no idea he had just become one.