Sherlock was sunk in his chair, arms dangling over the armrests, eyes closed, legs stretched out in front of him. John's footsteps on the stairs brought him up from his dense network of thoughts.

"Is it a two-patch problem then?" he heard John ask.

Sherlock pried his eyes open and looked from one arm to the other. He was vaguely surprised to see a patch on each arm. "Nope," he said languidly, "forgot about the other one."

John shook his head like his flatmate was hopeless as he carried groceries to the kitchen table.

"Any new developments?" he called back.

Lestrade had come through with the promised grave exhumations. Sherlock had been at the morgue all day overseeing the autopsies and testing blood samples.

"If you're interested in the fate of Mr. Tony Bauer I can tell you he's safe for the time being. His blood sample tested negative. No poison."

"Huh," John said. Sherlock watched as he opened the fridge and moved the new blood packets to the apparently less objectionable space on the fridge door.

"You may also be interested to know that the girl who died in the car crash—Amy Elliot—has traces of the poison in her blood."

"Really?" John said when he'd finished unloading the food and walked back into the living room. "But she didn't have scars."

"Bauer has scars but no poison, and Elliot has poison but no scars."

"And what do you make of that?" John asked, the perplexity in his voice indicating he was unable to make anything of it himself.

"Ideas, ideas," Sherlock responded listlessly. "Theories… possibilities…"

"So what's your best one?"

"The Woman."

"What?" It was one word but Sherlock could hear the edge in it.

He lifted his head and furrowed his eyebrows at his suddenly tense flatmate. "The Woman, surely you remember."

"Irene Adler?"

"That's the one," Sherlock said, dropping his head back.

"You think she's somehow… involved in this?" John asked incredulously.

"No," Sherlock replied, "I know she isn't."

"Then why are you mentioning her?"

In one of his mood swings Sherlock snapped from lethargy to energy as he leapt out of his chair. He walked to the wall where he'd pinned the pictures of the corpses. John followed him. This was his favourite part. In his mind he had a tangled web of theories. As he spoke them aloud they smoothed out neatly into a logical progression.

"David Rodgers: Death by poison. Dragged to an alley and stabbed postmortem as a cover-up. Neil Parker: Death by poison. Shot in his own flat postmortem and burglary staged as a cover-up. But these two…" He tapped the pictures of Brandon Riley and Amy Elliot. "They break the pattern in more ways than one. They died only days after receiving the poison. The poison was allowed to run its course in the other cases, killing the victims in about two weeks' time. Why were these two killed prematurely?"

"Maybe the car accident was really an accident?"

"Are you suggesting it's a coincidence?"

"You think it's a stupid suggestion."

"Quite."

"Well, don't mind me then," John said, glaring.

Sherlock knew how to handle it. "I rarely do," he said, pushing forward into John's space and earning a flutter of his eyelashes which broke the glare. John looked up at him with renewed attention and Sherlock continued, "The better theory is this: Amy Elliot's poisoning was a mistake. She wasn't part of the plan. An unexpected casualty."

John crossed his arms, listening. Sherlock liked the way John listened. It was much better than the way anyone else listened.

"There wasn't meant to be a connection between any of the victims. I think Elliot received the poison accidentally, and the murderer—or murderers—preferred to get rid of both her and Riley rather than risk a couple exhibiting the same symptoms or dying of the same poison."

Sherlock turned away and with a few strides he was back at his chair, dropping swiftly down into it.

"Besides the two of them there's no apparent connection among the victims." Sherlock leaned forward, balancing his elbows on his knees and steepling his fingers together. "Their deaths all look like isolated incidents, and whoever killed them wanted to keep it that way. But there must be something that links them. In order for all four men, if we include Bauer, to receive such similar scars they must have seen the same person, or people. However, my research shows they had no mutual work, family, or friends. What else connects complete strangers?"

John shrugged. "Maybe some kind of services, like a mutual doctor or dentist… hair stylist, I don't know…"

"Excellent, John! I thought of those possibilities myself. They are, of course, incorrect."

"What then?" John sat down in his chair across from Sherlock. His tone suggested he did not appreciate that his answer could have been correct in an alternate universe.

"Each of the men has a large number of these small scars, and each scar was made at a different time. Unless they were repeatedly being threatened—which is highly unlikely considering the background checks Lestrade ran on them—we have to assume they were electing to have these cuts made."

"Why would someone elect to have their skin cut?"

"Why indeed."

Sherlock watched John's face as he struggled to put the pieces together. Come on, John. I mentioned The Woman already. Put it together…

"Oh," John said finally, "you think it's a sex thing, like what Irene Adler did."

Sherlock grinned.

"Some kind of BDSM stuff," John mused.

"What's 'BDSM'?"

"Never mind. That's a bit rough though isn't it? Cutting people during sex?"

"The cuts were light, thin, which is why the scars are that silver colour. And the location makes them easy to hide."

"So you think there's a woman like Adler out there who you can pay to play Guantanamo Bay with you."

Sherlock held the armrests and jumped up onto his chair, sitting back on his heels. "Probably not one woman. The men who were poisoned were randomly chosen; that much is clear. There's nothing to connect them and there's nothing in their history that would make them targets. I would bet there are multiple women who provide the same service, but one of them one night had poison. Like Russian roulette. She had three appointments on one specific night, and those are them," Sherlock gestured to the pictures of the dead bodies on the wall. "Bauer was lucky. He must have seen someone else."

"Which explains why he has scars but no poison." Sherlock liked watching the moment John twigged. His blogger was just as eager as he was to find the puzzle pieces that fit together. And though it always happened for him a bit later than it did for Sherlock, he still enjoyed seeing the energy thrum though him at the moment of comprehension.

"But why would this woman poison random men?" John asked. "You think she's a serial killer?"

Sherlock sprang from his crouched position on the chair, striding over to his laptop. He sat down at the living room table and flipped up the screen.

"I think the dead men were guinea pigs. Randomly selected test subjects. I told you before the drug is new: they're testing it. I think the woman who administered the poison is merely a pawn in a much larger game. We have to find the king."

"So where do you want to start?"

A few strokes at the keyboard revealed the website he was looking for. Sherlock spun his laptop around so John could see the page for Monroe's Gentlemen's Club. "I don't think it's a coincidence that Riley and Bauer were at a strip club the Friday night before he died, do you?"

"Hang on," John said several hours later. They were both on their laptops, John in his chair reading an article about a new drug for narcolepsy, and Sherlock continuing his research at the table. "I asked you if you thought Irene Adler was somehow involved in the murders and you said you know she isn't."

Sherlock looked up at him, laptop screen illuminating his features.

"How do you know she isn't?" John asked.

Sherlock returned his attention to the laptop, clicking and scrolling. "Because she's in Berlin, and too smart to get herself wrapped up in any more English scandals after what happened last time," he said with a smirk.

Berlin. Sherlock thought she was still alive.

Suddenly feeling restless and too hot, John shut his laptop and stood up from his chair. He'd almost forgotten about the lie. The story Mycroft invented and John had relayed: A witness protection program in America…

He remembered the rainy afternoon years ago.

Mycroft's presence at Speedy's was odd to say the least. He'd given John the file as he stepped out to take a call and John hadn't decided whether he would tell Sherlock the truth or the lie even as he reached the top of the stairs.

Of course Sherlock knew immediately that he had something important to say, apparently just by the sound of his footsteps on the stairs, since the consulting detective hadn't even glanced up from his microscope before proclaiming John had news to tell him.

John hesitated, unsure, almost deciding on the truth, but then Sherlock looked up at him. John fumbled with his words. Sherlock stood and walked around the table, still looking at him like that. He was too close, and then he took a step closer. The smell of that expensive shampoo combined with the unique scent of his skin—something like the cold metal of lab tables and the electricity of adrenaline—it was as heady and overwhelming as it always was whenever Sherlock got too close and John chose the lie.

By the time Sherlock stepped back, and John's scattered thoughts were able to reorder themselves, he regretted what he'd said. He even got as far toward telling the truth as, "Actually—" before Sherlock interrupted him, asking for her phone.

It was the fact that he still wanted her phone, even after John told him it had been wiped clean that prevented John from trying again to tell Sherlock she was dead. Because it was sentiment. The phone was empty; the only possible reason Sherlock could want it was sentiment.

Downstairs Mycroft had suggested Irene Adler might have been the one woman who mattered to the detective and John had dismissed it: "He doesn't feel things like that."

Now he realised he might have been wrong, because Sherlock reached out his hand for the phone and said, "Please." The effect of the word was to deprive John of any choice in the matter. Sherlock pocketed the phone and remained immersed in studying whatever was under the microscope that day.

John lingered in the doorway, eyes transfixed on the scientist in the kitchen.

He never told him the truth.

John flexed his hands and took a deep breath. He hadn't been able to say it at the time. But he owed it to Sherlock to say it now. He walked over to where Sherlock was sitting and cleared his throat.

"Actually, she's not in Berlin."

Sherlock sat back in his chair and folded his arms. "Oh?" he asked, looking up at John through his fringe.

"Right," John cleared his throat again, "she's, well, actually… she's—she's dead."

Sherlock raised an eyebrow. "I don't think so."

"Well, she is. Mycroft told me after the, er, the whole… I meant to tell you, but—" John stopped.

"But what?" Sherlock leaned forward. He was looking at him in a way that kept making John look at the carpet.

John shook his head. "I don't want to upset you but I thought you should know."

Sherlock leaned back again and scoffed, "There's scarcely reason to be upset about a person living in Berlin. Granted it's a dreary sort of place but it's hardly cause for alarm."

John looked at Sherlock with concern. He knew the first stage of grieving was denial, but at the moment Sherlock had the sort of energy in his eyes that always gave John pause.

"Sherlock, she's not in Berlin; she's dead. Terrorists got to her in Pakistan. Mycroft said he was absolutely certain."

Sherlock squinted at him in a way John knew he used to affect keen interest. "Really. And what else did my dear brother say?" His eyes gleamed as he waited for an answer.

"He said he was thorough. They checked the details; it was definitely her. He said it would take you to fool him…" John trailed off as it dawned on him.

Sherlock grinned.

John's mouth fell open. "You, you didn't—"

Sherlock raised his eyebrows.

"Sherlock, you flew to Pakistan? You saved her?"

"Never trust a beheading; you never know whose head you're missing."

John gave a short, humourless laugh. "I'm going to have a hard time believing anyone is dead after this."

Sherlock pointed to the skull on the mantelpiece. "He's dead."

John scowled. "Thank you."

Sherlock jumped up from the chair and walked over to the wall where he'd pinned the pictures of the corpses with all of their information. He clasped his hands behind his back as he studied the layout.

Recovering himself a bit John realised he was not ready to drop the conversation.

"But, why?" he asked. "I mean, obviously it's good to save people; I'm not saying you shouldn't have saved her—" he checked his rambling. He took a breath. "I didn't know you cared about her so much." John let his eyes hover on Sherlock's back, hoping for an answer to the unasked question.

Sherlock didn't turn around. "A mind like hers would be a terrible thing to waste," he said.

Not really an answer.

John stuffed his restless hands in his pockets. "Have you been in touch with her?"

"No."

"Then how do you know she's in Berlin?"

Sherlock shrugged. "Twitter. Different name, different identity, same profession, definitely her."

John rocked back on his heels to get a look at the ceiling. "You knew. All this time you knew I was lying."

Sherlock did turn now. "Did you think I didn't?"

He walked the few paces back toward John until he was standing directly in front of him, aggressively close. The master of deduction moved his eyes slowly down his face and the length of his body before dragging them back up again. John swallowed reflexively and fought the urge to step back. It was moments like these, when Sherlock focused on him, that he felt the detective could see right through him. In some ways John knew he could. When Sherlock finally spoke his voice was low, the deep pitch that would have held John in place even if he'd wanted to back away.

"I can read your thoughts before you've even entered the flat by your tread on the stairs. Do you think I don't know when you lie?"

John locked his eyes on Sherlock's. "I will lie to you when I want to," he said evenly.

There was a flash of something in Sherlock's eyes and he grinned. "Good," he said. He dropped John's gaze and John was surprised to see him hesitate for a moment. He looked back up at John for a second before turning away.

"Berlin isn't far," John couldn't let the point go unremarked. "It's not far at all."

Sherlock walked back to the pictures on the wall.

"Why haven't you contacted her?"

He yanked one of the crime reports off the wall. "Why would I want to contact her?" He sat down again at the table.

"Well, you went to the trouble to infiltrate a terrorist organisation for her. I wouldn't think meeting her for coffee would be right out. Or, you know… dinner…"

Sherlock threw a glance at him before looking back at his laptop. He began typing and John knew he shouldn't, but the question had been nagging him for years. He hated himself a bit for needing to know. But he did. He needed to know, and he wouldn't get an opportunity like this again. He decided to throw caution to the wind, and simply hope it wouldn't get blown back in his face.

"Why don't you want to see her?"

Sherlock's eyes didn't leave the screen. "Why didn't you tell me she was dead?"

John dropped his head and bit his lip. Right. He went to the kitchen to make tea.