Some months later, John is going through the remaining stuff in his cupboard. He’s in a purging mood, and has decided that anything he hasn’t looked at in the past six months, with the exception of photographs and army mementos, needs to go.

He’s digging through a box that pretty much only contains terrible clothing gifts from Harry, going back to his army days, when he comes across an unlabeled envelope. He opens it and reads in Sherlock’s writing, “Karachi, Pakistan”.

John stares at it, confused, for a moment. Then it dawns on him. This must have been from one of Sherlock’s trips, his note on where he’d gone in case things went wrong. How he’d expected John to find it in a box he hadn’t gone through in several years, John has no idea, but it is rather consistent with Sherlock’s thought process. But which trip had this been? He’s only been gone a few times in the past year, since their agreement has been in force.

Suddenly, he remembers his conversation with Mycroft, weeks ago. Irene Adler had been killed by a terrorist cell in Karachi. He hadn’t had the heart to tell Sherlock. But now it seems like he hadn’t needed to. He finds a mix of anger and empathy swelling within him.

He sits carefully, waiting until he can think rationally about this. Once he’s worked it through, he gets up calmly and goes downstairs. Sherlock is in the bedroom, resting after a particular convoluted and energetic case of drug smuggling. The time spent in the meat locker had been particularly exhausting for them both.

John walks into the bedroom quietly. Sherlock is lounging on the bed in pajamas bottoms and an inside out t-shirt, eyes closed but not asleep.

“Hey,” John says neutrally, approaching the bed. “Can I talk to you for a minute?”

“Can I stop you?” Sherlock replies, not opening his eyes.

“Probably not,” John admits. Sherlock and props himself up on his elbows. Keeping frustration and hurt out of his voice as far possible, John asks “Why didn’t you tell me you went to rescue Irene Adler?”

Sherlock’s face twitches, but manages not to betray any strong reaction. “Why did you tell me she was in a witness protection scheme in America when you knew she was dead?”

John feels a pang of guilt for a second, unless he remembers that he only lied because he was afraid if Sherlock knew she was dead, he might just self-destruct.

“Well, she’s not dead, is she?” John retorts, sharper than he means to. He sighs. “Sorry. I just feel foolish now. I’m not angry, not really. I’m glad she didn’t die, she didn’t deserve that ending. I just want to understand. That’s all I’ve ever wanted.”

Sherlock finally opens his eyes and gets up reluctantly, facing John cross-legged. “I’m not sure I can explain.”

“Try,” John says firmly. “I’m not jealous anymore. But I want to know you as much as I can, and this is a part of you I just don’t know. I won’t react badly, whatever you say. Just…please try?”

Sherlock nods reluctantly and takes a deep breath. “I know you think I’m obsessed, infatuated. You’re right, I am. Have been. It’s not because… it’s not an attraction. Not like you would think. I am…drawn to her. Because… John, this is embarrassing!” he says suddenly.

“There’s nothing to be embarrassed about,” John assures him. “Whatever you feel, you feel, I just want to know. Isn’t that what this is all about? Knowing each other?”

“Fine,” Sherlock agrees grumpily. “The fascination is… that… she is… me…”

“She’s you? No she’s not!” John exclaims. “You couldn’t be more unlike. Well, except that you both are a bit heartless and possess a strange amorality that few people share.”

Even as John protests, he can see it. She’s crueler than Sherlock, unhampered by any affection, and she prefers the mystery of the man to the mystery of the crime scene, but there is something there, some spark they’ve recognized in each other.

Sherlock makes a noise of frustration. “But we are the same. And yet not. Or at least… she’s who I might have been. If I’d been born different, if I’d been female. She’s just as clever. It’s merely a different kind. I’m clever about facts, she’s clever about people. She can read a person, a social situation the way I read a crime scene. She’s like an alternate history to myself. All the skills I lack, she possesses.”

John takes that in. “So, you’re saying she’s…a different version of you?”

“Yes. No. I don’t know.” Sherlock is breathing too fast, unable to put it in to words, nervous that John will end up mad at him again.

“Okay,” John tells him, “It’s okay. Just tell me what you can.”

Sherlock licks his lips. “I need her to exist. That’s why I saved her. She’s like… my equal and opposite force. She’s the balance to me in the universe, what might have been. Not like Moriarty. He’s what I could become but mustn’t. And not like you. You’re my complement, my other half.”

The Woman, the Villain, and John. What will never be, what could be, what is now. These three people tell Sherlock who he is. And who he’s not.

Sherlock continues, “You, I need to be a person, to make me whole. Her, I need as a counterweight, to stand in relief. She’s my negative polarity. Or maybe I’m hers. We orbit each other, in each other’s influence but if we get too close everything burns. As long as she exists, I can exist. If there’s not hope for her… I think there might not be any hope for me.”

“You… need me in order to be a person?” John asks, stunned.

“That… wasn’t really my point,” Sherlock says. “But, yes, if you need to know. I should have thought it was obvious.”

“Sherlock Holmes, you are the most breathtaking moron I’ve ever encountered,” John tells him. “But then I’m not much better.”

Sherlock looks confused. “You understand then?

“Not really. I’ve never had something like that, I’m not sure I can ever really understand it. But I can understand what it means to you. And I understand what a fool I was to think that you would let her come between us. I’m sorry.”

He leans forward and sits next to Sherlock who exhales slowly. “I… regret… if any of the ways I have behaved made you doubt your importance to me. I was distracted. I didn’t ever expect to meet someone like her. Like myself, and unlike. Trying to puzzle it out took more of my attention than perhaps it should have.”

John sometimes aches to see Sherlock struggle with concepts and feelings most people understand so well they hardly need to explain them. He has to construct metaphors and invent terms just to be able to grasp what’s going on within himself. Everything that has to do with people, with their emotions and his, and their relation to each other, is a battle for him. No wonder he finds refuge in the coldly logical so much of the time.

“Apology accepted,” John whispers.

“Likewise.” Sherlock is trembling from the energetic cost of an explanation like this.

“I was just so afraid of losing you. I went a bit barmy. You’re my dark matter,” he tells Sherlock, “You can’t always see it, but you make up ninety-six percent of my universe.”

“A beacon in the North Sea,” Sherlock replies, fervently, glad to be speaking a language he understands again.

John smiles and Sherlock responds in kind, and suddenly neither of them are thinking of Irene Adler, nor will they for a very long time.