John took himself upstairs to his old bedroom, the floorboards creaking forlornly under his weight.

He was angry and he knew he was deliberately distancing himself from Sherlock but he knew staying downstairs would make things worse. He would pick a fight. He wanted to pick a fight, which was so unusual for him that he had forced himself up the stairs and sat on the bed, arms folded, legs crossed, feeling even angrier.

He wasn't especially angry with Sherlock and that annoyed him. He wanted to be – he felt like he could have been justified in it, but part of him recognized that as untrue. It irritated him that he was being so ridiculous, like a little child who hadn't got his way.

Like Sherlock.

John sighed, raising a hand to pinch the bridge of his nose, closing his eyes against the shadows that defined the dusty darkness. He tried to muster up some righteous indignation but he knew Sherlock was right – it wouldn't have mattered what assessments the detective could have given him. John would have picked the one he liked and gone right on investigating anyway.

Which left him angry with himself. And angry with John Riley for not knowing who he was. It irritated him even more that Sherlock was also right that Riley hadn't been lying to him. He couldn't have been – he barely knew anything about himself.

He felt stupid and foolish and he didn't think it was all fair that Sherlock was being the reasonable one here. That was John's job. Sherlock was meant to be the petulant moody one, the one who took offence at an offhanded remark, the one who lost his temper at the slightest provocation, the one who would sink into a sulk for hours on end.

It didn't help John's mood that he knew full well he was sulking. Lying on the spare bed alone the darkness, he felt like a child who'd had a toy taken away.

But it wasn't a toy, it was a terrorist. The word made John feel unsettled again. Not angry. Confused. It didn't add up – but Morgan knew Riley. He'd been arrested in Dublin eight years ago. She had files and confessions and evidence.

And Riley had turned to John for an explanation.

John could still see him, confused, uncertain as to what any of it meant, looking for an answer.

From the man who always did his best to provide them.

John sighed and rubbed his hands over his face, cursing quietly to himself. He slouched all the way down on the bed until he was lying on his back, staring through the darkness at the ceiling. A faint light came through the open door from the living room where he could hear Sherlock moving around. He'd let John go upstairs without comment and not the kind of lack of protest that meant he was going to be huffy. Just a simple nod, and John had felt those intense grey eyes following him up the steps.

He interlaced his fingers on his stomach and sighed again.

A few minutes later, he heard the faint strains of violin music drifting up toward him – just scales at first as Sherlock warmed up, transforming into soft Christmas carols that made John close his eyes. He could picture their tree downstairs, decorated, glowing gently with its green and red lights. He still had to dig out the stockings that Mrs. Hudson had made for them the first Christmas they were married. Sherlock had acted appalled at the idea of a personalized stocking but had secretly been delighted.

John felt his lips twitch at the memory.

The music stayed soft, winding from one melody to the next, and he began to feel sad. He opened his eyes again, thinking of everyone he knew. Mrs. Hudson having her niece and her family for the holidays. His mum with her sister at their cousin's in Lincoln. Tricia and Henry at home with their daughter. Bill and his family in Portsmouth with his in-laws. Lestrade at home with his wife and kids. Mycroft – John's lips twitched. Even Mycroft up in Buckinghamshire with William, Angela, and David.

And the man in the hospital with no memory.

He sighed, and rubbed his eyes.

The music filled the room and John felt alone.

He got up and padded back down the stairs to curl into his chair in the living room. Sherlock glanced over his shoulder at him but kept playing without comment. John sat and listened in silence, closing his eyes and feeling at home.

The next day, he went to meet Charlotte Morgan at Scotland Yard.

Donovan wasn't happy with him and she didn't bother trying to hide it. By the drawn expressions on the faces of both women, they hadn't had much sleep the night before. John felt a moment's guilt – he'd actually slept fairly well once he'd fallen asleep, wrapped in the cocoon of long limbs that was Sherlock.

This wasn't his job, he reminded himself.

And yet, here he was.

But Morgan shook his hand despite the glare Donovan aimed his way and gave him a tired smile that wasn't entirely faked. Despite the London DI's exasperation, the Irish inspector seemed glad he was there. She led him to an office that seemed to have been temporarily assigned to her then rounded up a constable and sent him for coffee with all the self assured authority of someone used to giving commands, even if this wasn't her own jurisdiction. Then she closed and locked the door behind the departing officer before settling behind the desk, across from John.

"Donovan's explained to me about you and your – sorry, what's the term you prefer?"

"Husband," John replied and Morgan smiled slightly, nodding. John didn't think she was much older than him, if at all – eight years with Sherlock had taught him to be very good at judging ages and he liked to tell himself he'd taught Sherlock a thing or two about tact in that regard.

"You and your husband," Morgan continued. "She showed me your blog."

John felt himself colouring and her smile grew and warmed somewhat.

"It's an– interesting life you lead, Doctor Watson."

"It has its moments," John agreed.

"What about John Riley?" she asked.

John frowned slightly, resisting the urge to shift in his chair. Even though it wasn't an interrogation room, he still felt like he was being questioned by the police. Which, point of fact, he was.

"What about him?"

"Donovan showed me the notes you took, too, the ones she photocopied. I assume you have more, and I'd like to know what you know about him that you didn't write down."

"Well apparently, I don't know anything about him at all," John replied. "He's your informant, he works for you."

"He was," she said, her expression turning serious, "and he was exposed four years ago, at which point he stopped working for us and we started working for him."

John frowned, shaking his head.

"New identity, new life, Doctor Watson. Keeping him safe. We have regular contact with him – but his attack came shortly after he last reported in. I would have had no reason to suspect anything had happened to him until shortly before New Year's. And now I have to worry that I've failed in my job because someone may have found him. If this wasn't random..."

"You're worried someone tracked him down here."

"Yes," she said plainly. "He helped us put a number of people in prison, but some of them have served their sentences. And some of them left behind families who would might object to the price of Riley's freedom."

"You do, don't you?" John asked. Morgan sighed.

"We don't negotiate the deals," she replied. "If this had been my choice... I may have made a different one. I see it's value, though. We need people like John – he got us information that stopped a number of other RIRA members."

"Why did he do it?" John asked. It had been the question that had plagued him the most all night – what had made him change his mind?

"Does it matter?" Morgan asked.

"It matters to me."

"Why?" Her question was simple, her tone straightforward. John searched for face, looking for some hint of judgment but found none. He wondered if she was hiding it, if she could school her features that well. Probably well enough to fool him, he thought.

He hesitated a moment, debating his answer.

"He's my friend."

Morgan regarded him thoughtfully for a moment then smiled slightly, giving a dry chuckle that was little more than a sharp exhalation.

"He could do a lot worse than you, Doctor Watson. He has. As to his reasons..." She paused, pressing a hand over her lips, looking away. John waited, letting the silence stretch until he thought he wouldn't get an answer, then Morgan refocused with a small shake of her head.

"Someone died. His son. He was only three."

John felt a cold shock and swallowed on it, nodding numbly.

"You can say it's tragic – it was. And selfish. A lot of other people's children died because of the work he did."

How many? John wondered. Then: And how many didn't die because he did change his mind?

"What about Patrick Connolly?" he heard himself asking. Morgan's eyes flared, narrowing hard.

"What do you know about Patrick Connolly?" she demanded.

"Um," John started, caught off guard by her sudden vehemence. "Not much – only what Lestrade told us when he came to see if Sherlock would take this case. He was killed in an art gallery in Mayfair – the Gossard Gallery – but they never solved the case. There were a number of fingerprints they couldn't identify, but one of them was a partial match to John's. The police thought if it was his, if he was there..."

"Oh, I don't doubt John Riley was there," Morgan said and John felt a flash of shock tighten the muscles along his spine, sending a warning flare through his shoulder. "Whether or not he was actually present when Sergeant Healy was killed is another matter altogether. We've never been able to prove that he was – and he'd have no reason to tell us if he had been."

"What?" John asked. "Who's Sergeant Healy?"

"Patrick Connolly, Doctor Watson. At the hospital, you asked if John Riley was an undercover cop and I said no. But Patrick Connolly was. Sergeant Finn Healey. He'd made it into RIRA and stayed there for almost a year and a half – then he was murdered. It's been twelve years and we still don't know who killed him."

John wasn't sure how he'd ended up in the ensuing meeting but he didn't ask, opting to stay silent and more or less forgotten in his seat while he looked through Connolly's case file. Donovan and Lestrade were both there now, standing next to each other in a face off against Morgan. He felt almost invisible, small and unseen, like a witness to a war.

But if I blog this, will they arrest me? he thought. Probably.

"The former gallery owner was loosely associated with RIRA – providing funding routed through charitable organizations," Morgan was saying. "She provided the space as a meeting place after-hours but never had any more direct involvement, as far as we could ever determine."

"As far as you could determine?" Donovan snapped. "We looked into her records twelve years ago and there was nothing suspicious at all!"

"You didn't know who Healy was," Morgan pointed out.

"No," Lestrade said and John was startled by the ice in his voice. "It seems that you force has been withholding information from us that could have helped us solve this case. Twelve years. A man's death has gone unsolved and unpunished for twelve years. Is that all right with you?"

"Of course not," she snapped, dark eyes flaring. "He was one of us, Inspector."

"That's why we needed to know! A police officer–"

"An undercover police officer who was murdered. We don't know why – you're going to say it's because he was discovered but we have no evidence of that. We don't know who did it, we don't know why they did it. And because we don't know, we couldn't risk exposing his identity to anyone. If no one knew who he was, if Patrick Connolly was murdered for some reason other than really being Finn Healy and if we had gone public with that information, everything he'd worked for would have been lost. Do you imagine he was the only undercover officer we had in an IRA group? Not a chance. Anything, any hint of this would have driven RIRA – and the rest – so far under the ground we'd never had found them again."

"And if you'd have let us do our jobs we might not be here right now having this conversation!" Lestrade snapped back.

Morgan shook her head firmly, blowing an irate sigh between her lips. John spared a glance at her, before frowning at a photograph of the body, tilting it to get a different angle.

"Do you think this was my decision, Inspector?" Morgan snapped. "Twelve years ago this was not my case. I didn't know Healy. The case is mine now but the decision still isn't – I still have to follow orders."

"And would you have told us if it was your decision?" Donovan demanded.

"Does it matter?" Morgan sighed. "It wasn't ever going to happen. You found nothing and we were in possession of more information and all of your facts and we didn't find anything either. Someone knows who murdered Healy, but it isn't me."

"Is it John Riley?" Donovan asked.

"Do you mean, does he know who did it or did he do it?"

"Both. Either."

Morgan sighed again, drumming her fingers on her desk.

"He was there," Donovan pointed out. John nodded to himself as though she'd been speaking to him – he had been there, even if he didn't remember. No doubt of that now. But had he held the knife? The doctor flipped through the notes again, frowning, eyes skimming the description of the fatal wound.

"Yes, he was there. That day, that time? I doubt it. He probably knows, but he's never said anything. He was interviewed about it when he became an informant but nothing in the interview suggested he had any idea."

"What about the gallery owner?" Lestrade snapped. "Why didn't we find information on her? Did you bury that too?"

"She buried it," Morgan retorted. "We knew she was involved in RIRA, that's how we were able to trace it. Those weren't faked charities, Inspector, they were real. Their finances were managed by different accountants but the same firm – giving one person access to all of them. Money was skimmed, here and there, but carefully and it was well covered."

John glanced up again to see Donovan and Lestrade glaring at Morgan before the DI sighed, pinching the bridge of his nose.

"Whatever money she may have kept giving them, they never used the gallery again," Morgan continued. "We didn't just lose a good sergeant when Healy died, we lost a lot of information."

"Until Riley turned informant," Donovan said.

"Until then," Morgan agreed.

"He's got to know something," Donovan murmured and John raised his eyes again, a warning on his tongue. She was looking at Lestrade, who gave a curt nod.

"What will you do?" Morgan said. "Arrest him?"

"Perjury? Accessory after the fact? I could make those stick," Lestrade answered.

"You could even make a case that he murdered Sergeant Healy," Morgan snapped. "That doesn't mean he did."

"He didn't," John replied and there was a pause before their gazes swung around to him, making him aware that he was suddenly the subject of intense scrutiny by three high ranking police officers.

"John, I know you've become friends with him–" Donovan started. John shook his head, cutting her off, wondering for a moment if this was how Sherlock felt on a case, when he hit on that one detail no one else had spotted yet.

"It's not that. Look," he said, holding out the file, open to the picture of Healy's body and the coroner's notes regarding the wound. "The description of the stab wound. Healy was stabbed by someone holding the knife in his right hand. Through the muscles in the back and the ribs and into the lungs? That would take a lot of force."

"Yes," Donovan agreed. "And?"

"John Riley is left handed. He might know who did this, Sally, but it wasn't him."