When John opened the door to the flat he was not surprised to find Sherlock with his violin at his shoulder. He'd heard the music from the street as it drifted through the open window. He was quite taken aback, however, to see his flatmate dressed to the nines in a strikingly smart tux with his hair even more precisely arranged than usual.

John gaped at him. "Wha—Why are you dressed like that?"

The detective seemed built for formal dress—a point which clearly hadn't escaped him, due to the extreme 'pyjamas or suits' dichotomy of his wardrobe. His long legs and lean figure were precisely what suits were designed for, and it showed. But this tuxedo was something else entirely.

John paused looking at the fashionably slim trousers and the sleek cut of the jacket. He'd seen this suit once before.

"Where's Sherlock tonight? I thought you would be at his place," Mary said, standing in the doorway of their bedroom.

John looked up and saw her mouth pressed to a thin line.

"I'm not always at his place," he said, chafing at the insinuation. "I haven't seen him in weeks."

Mary remained silent, sliding the pendant on her necklace back and forth on the chain.

"He's out tonight anyway," John said, returning his attention to the gym bag he was packing. "Mycroft basically blackmailed him into going to some function."

"You're avoiding me," Mary said.

John hung his head. He was not in the mood for this conversation. He hadn't been in the mood for it for almost a year now.

"I'm not—"

"You are. Sherlock's off tonight and you still have to leave the house."

"I don't have to leave. I want to go to the gym."

"Then stay in tonight, if you're not avoiding me. Eat dinner here for once."

John met her eyes and knew that while it wasn't an ultimatum, if he refused it would be another fissure in the glass. Fragile glass that had been shattered and haphazardly stuck back together—there were pieces missing and pieces that no longer fit together. The result was a poor, precarious imitation of what was once smooth and solid.

John didn't want to stay in tonight, but he had chosen to stay married to her. He could have left her back when everything had gone to hell. But he didn't. And he was grudgingly aware that it wasn't fair to have chosen the marriage and then to neglect it. He either had to divorce her or at least try to make an effort.

Dinner was an unremarkable affair. They made the typical small talk about work. They'd met when they were working at the same surgery several years ago. But now (thankfully) they were at different locations. They smiled a bit, exchanging stories about patients.

As they cleared off their dinner plates and Mary asked hesitantly if he would like to watch a movie with her John saw a glint of hope. Under the constant cloud cover of their relationship he could sometimes see these infrequent flashes of light. As though it were possible that one day the sky could clear.

Unfortunately, more often than not, these moments came coupled with a reminder of why they were in the situation to begin with: a mental picture of Sherlock the way he'd been in Magnussen's office when John had rushed into the room, not realising the full extent of what had happened until he pushed his friend's jacket back and saw the blood, gasping for breath as he reached for his phone, oh my god, dizzy the way blood never made him, the fury flooding upwards as he demanded, "Who shot him?" And just like that the light blinked out, so easily enveloped back by the thick clouds.

He gave Mary a thin smile. "Sure." He sat on the couch with her, let her pick the film, and wondered which of these days he would have to give up on a hopeless situation.

It was around ten o'clock and they were halfway through the film when the doorbell rang. Mary looked questioningly at John, who shrugged. Standing, he muttered, "I'll see who it is."

John opened the door and took an involuntary step backward when he saw his ex-flatmate on the steps, a taxi idling behind him on the street. John hadn't seen him in weeks; if he'd forgotten even a bit how arresting was the appearance of Sherlock Holmes, he was duly reminded now. The consulting detective was sharply dressed in an exquisite tux, thick black curls styled to perfection, standing on the doorstep with his hands in his pockets.

"Sherlock! What are you doing here?" John asked, stepping out and shutting the door behind him. "You look, erm—" John was not at all sure why he had started that sentence, or where it was going. Fortunately he didn't have to finish it.

Sherlock cut in, "Yes, Mycroft seems to think it necessary I put my torture-resistance training into practice every now and then, lest I forget it."

"You—what?" There were clouds covering the moon and Sherlock's ivory skin was striking against his dark hair, against the dark night.

"I have spent the past four hours socialising with the majority of the English landed gentry."

John grinned, folding his arms and leaning against the doorjamb. "Sounds dreadful."

"I managed to evade all passive-aggressive tactics to prevent me from leaving."

John shook his head in feigned admiration. "Lesser men have been trapped at parties for much longer."

Sherlock grinned. "How about chips? There's nothing worthwhile in this neighbourhood; we'll have to get out of here."

"Is it possible Sherlock Holmes is hungry?"

Sherlock scowled. "They had only miniatures of food at the party, and the fat people were guarding it."

John tried not to laugh. "Shame," he said.

"So, fish and chips? Or cake"—Sherlock put on his most benevolent air—"you can choose."

John stepped off the wall toward his friend, but he stopped. He looked back at the house. "I can't."

Sherlock followed his gaze toward the lighted upstairs window. When he looked down again his eyes pierced through John's. "Are you sure?"

John's eyes flicked over his ex-flatmate. He wasn't sure. He wasn't sure about anything. He wanted to leave the steps and go off into the London night. With Sherlock there was no telling what could happen any time you walked out the door. He wanted to get his gun and jump into the cab and go wherever Sherlock would take him, even if it was just for chips, or cake (damn it John was awfully fond of mad detectives who showed up at his door in tuxes offering him the choice between chips or cake). But he felt tied to the door by his responsibilities and it made him resent them doubly.

Sherlock was standing in front of him looking a world apart from the ordinary. One of the beautiful people—his intelligence a palpable energy, the potential for danger woven through his genes.

Why did it have to be tonight? After the conversation he'd had with Mary earlier, he couldn't. He had chosen to try to repair something. Maybe one day. He hoped one day…

John swallowed. "Yes, I'm sure. Maybe another time."

Something flickered in Sherlock's eyes. "Suit yourself."

John fought an impulse to reach out and grab him as he turned back down the steps. He watched him duck into the waiting cab and drive away.

Fuck, John thought.

Sherlock blinked at him and John felt a cold wave wash through him. "Oh god, the ball," he said, bringing his hand to his forehead. "For Mrs. Hudson I completely forgot."

"It begins in an hour and a half," Sherlock said. "You have plenty of time." He plucked at the violin strings absently as if deciding what to play next.

It had been a longer than usual day at the surgery and when John checked his watch it confirmed the time was already six o'clock.

"Look, erm," John said. "I don't think I'll go."

Sherlock plucked more strings.

"Can you just, er, tell Mrs. Hudson I'm ill or something?"

"The doctor is ill," Sherlock said, "how concerning."

John sighed, "I couldn't go if I wanted to. I meant to pick up something to wear this week but it slipped my mind."

"Hm," Sherlock said, moving over to his music stand.

"She doesn't need both of us to go," John said, aware that he was now probably talking more to his guilty conscience than to Sherlock. "As long as you're going I'm sure she won't mind if I skip it."

"Stay here if you like," Sherlock said, shuffling around the music sheets until he'd found what he was looking for, "but proper attire is no excuse."

"Sherlock, I told you, I don't have—"

"You do."

"What are you—"

"Upstairs," Sherlock indicated John's bedroom with a tilt of his head.

Sherlock began to play, and with no small amount of trepidation John made his way upstairs.

Sherlock wasn't halfway through the sonata when John came clomping back into the living room.

"What is this?" he asked, holding up the three-piece suit by the hanger.

Sherlock lowered his violin. "Do you want me to make a joke by saying it's something other than a tuxedo?"

"No," John said slowly, "I want you to explain why it's in my bedroom."

"It's a penguin," Sherlock said a bit belatedly, but the setup for a joke had been there and he didn't want it to go to waste entirely.

John gave him an exasperated look. "Sherlock, this material is nice, really nice. It must cost at least as much as my wedding suit, and I know how much I spent on that. I mean, thank you, but I can't accept it. No way. It's too expensive. I won't wear it."

"I didn't pay for it," Sherlock said.

"What?"

Sherlock shrugged. "You did."

"What?"

Sherlock sighed. Goldfish level: "Where is your credit card?"

"In my wallet."

"Did you use it today?"

John thought for a moment. "Well, no—"

"Then how do you know it's there?"

John grabbed his wallet out of his back pocket and flipped it open. His card was gone.

"You stole my credit card!"

"Excellent deduction. I would congratulate you on solving the case, except I'd say you lose rather a lot of points for not noticing there was a case in the first place."

"Why did you do that?"

"Because, John, you are tediously predictable and I knew that you wouldn't wear it if anyone else bought it for you."

"You can't just use my credit card to buy something like this. I can't afford it!"

"You can," Sherlock returned. "Consider it your 'I No Longer Have Mortgage Payments' gift to yourself."

John shook his head. "I'm returning it."

"Afraid that won't be possible."

John closed his eyes. "Why?"

"Because the receipt has gone missing. And they won't accept it back without it."

John gave him a hard look. "Gone missing, has it?"

"Indeed."

"Sherlock—" John said in a tone Sherlock didn't like to hear his name in.

"Every man should own at least one good tux. Just try it on before you make any decisions."

John exhaled, "Fine, I give up."

Sherlock watched his flatmate walk agitatedly back up the stairs and wondered if it was just John who got upset about having nice things or if it was a more widespread phenomenon.

By the time John got out of the shower it was still only six thirty. He looked at the receipt-less tux on his bed. Sherlock Holmes was nothing if not manipulative.

However, since it was here… He supposed it wouldn't hurt to try it on. Above all else he was curious to see what Sherlock would have chosen for him.

John did the last button and looked at himself in the full length mirror on the door of his wardrobe.

He straightened his shoulders. Turned a bit. And faced forward again.

If Sherlock hadn't thrown out the receipt, John would have shredded it. It was, by far, the most flattering thing he'd ever worn. It fit him somehow even better than his wedding suit. The cut was slimmer and the material exquisite. It had obviously been tailored exactly to his measurements.

He smiled in disbelief. Sherlock knew his measurements. John had never told him. He'd gone up and down in weight in the last two years, but the suit was precise. John supposed that's what you get when you live with a snobbishly fashionable consulting detective.

And what you get—John turned sideways in the mirror—is really not bad. Not bad at all.

Sherlock was playing again when John re-entered the living room. He coughed in attempt to swallow his pride. He was going to wear the suit tonight, and any other occasion that could possibly warrant it.

Sherlock stopped and turned around. John had the satisfaction of watching the detective's eyebrows leap up beneath his fringe before his face resumed its trademark nonchalance.

Sherlock cleared his throat. "The size seems to be accurate."

"Impressively accurate."

Sherlock smirked, "You can have that written on my next gravestone."

John grinned. "The first one was a bit plain."

Sherlock briefly returned the smile before looking back to his music.

John checked his watch. They were to meet Mrs. Hudson downstairs in twenty minutes. "Do you want a drink?"

"Sure."

John went to the kitchen and took down two tumblers. He didn't bother asking what Sherlock wanted. The official drink of 221B was Scotch and soda.

Sherlock was marking some notes on his sheet music when John returned with the drinks. He handed one to his flatmate and sat down in his chair. Sherlock joined him a moment later, sitting across from him.

"I've arranged a meeting for us with a prostitute."

John swallowed too quickly and the whisky burned the back of his throat. "A prostitute."

Sherlock waited.

"Oh, the prostitute you think poisoned Rodgers, Parker and Riley."

"One that works for the same... establishment. I have good reason to believe the woman who killed the men is dead too."

John raised his eyebrows. "Why do you think she's dead?"

"I spent the day undercover. I talked to people. She hasn't shown up for work. And if our killer really did use her to poison them, there might be good reason to do away with her afterward."

"So we're meeting with a random prostitute who works at the same club."

"The fact of her working at the same club precludes randomness."

"I assume she thinks the appointment is for sex," John said glumly.

Sherlock furrowed his eyebrows. "She wouldn't be likely to agree if I told her it was for a criminal investigation, would she."

"Well, this should be interesting." John took a drink. "You sure you want me to come? It seems a bit awkward—"

"It will be imperative that you do."

John thought the information that his role would be 'imperative' for an appointment with a prostitute did not bode well. "Where are we meeting her?" he asked warily.

"Monroe's. Tomorrow night. Ten o'clock."

"I'm not going to have sex with her."

For John it was stating the obvious, but with Sherlock you could never be sure. He would do anything himself for a case. Actually, John remembered suddenly, anything except this. If Sherlock tried to convince him to have sex with the prostitute for the case, then John wouldn't hesitate to remind him that he hadn't even had sex with his girlfriend for a case.

"You shouldn't have to."

"Shouldn't?"

Sherlock rolled his eyes. "You won't have to."

"Do you know how incredible it is that I'm even considering trusting you?"

"I am perfectly trustworthy."

"You spend ninety-percent of your time deceiving people."

"Nonsense."

"You're lying right now."

"You've lost your sheep."

John gave an incredulous laugh. "What?"

Sherlock frowned. "You know the phrase. 'Lost your sheep.' It means you've gone mad."

"I've never heard that before. That's definitely not a phrase."

"It is. It comes from the old days when a shepherd would be in such trouble if he lost his sheep that he could lose his wits."

John laughed. "Really."

"Yes, really," Sherlock said defensively.

John shook his head. That was the problem with logic. You could have a perfectly logical explanation for something and still be completely wrong. But for Sherlock logic functioned so accurately in his work that the (in some ways, surprisingly naïve) detective hadn't quite learned how it can fall apart in life.

But he decided he would let this one go. When dealing with Sherlock Holmes, John had learned to pick his battles. Because if he hadn't, well, he would have lost his sheep a long time ago.