Disclaimer: Sir Arthur Conan Doyle owns the original characters; Steven Moffat and Mark Gatiss own much of the rest.

It began, as did many things concerning Sherlock, with a text.

Pass me my laptop. -SH

Sherlock, I've been at the hospital for five hours. I told you I had to go. -JW

While you're there, pick up the feet Molly's saving for me. -SH

I'm not coming home. I'm with Harry. She's got alcohol poisoning. I told you this. -JW

When John trudged into 221B two days later, Sherlock wasn't there. John kicked off his shoes and collapsed on top of his blankets while still wearing his clothes. When he woke up, he ambled downstairs in pursuit of food that was not reheated in the hospital cafeteria. Sherlock was sitting in his usual chair, violin in his lap.

Sherlock frowned at John. "You said you weren't coming home."

"I didn't mean never." John opened the refrigerator and peered into it. Ugh. Clearly Sherlock hadn't visited the shops or thrown anything out while John was gone. It seemed that half the refrigerator's contents had gone off. "Don't you throw anything out?"

"Eating's boring."

John shut the refrigerator, whose smell was getting to him, and whipped around to face Sherlock. "Do I have to take care of you, too? Because I've already got one person I care about at death's door, and I don't know if I can handle another."

"Of course you can. You were an army doctor, for God's sake."

"You and Harry are both different from any of the army lads and you know it."

Sherlock tipped his head back and forth. "We've both lived with you in more private settings, it's true. And she's female and I'm a genius; you probably didn't get a lot of those—"

"You're doing this on purpose, aren't you?"

"What?"

"Missing the obvious."

"The obvious? What's obvious? What am I missing?"

"That you and Harry matter . . . a whole lot more than anyone else I've ever met."

"Well, given that you weren't on speaking terms with Harry for the better part of last year, I think I'd be forgiven for missing—"

"Have you ever heard of loving someone too much? Of not being able to forgive them precisely because you love them?"

Sherlock rolled his eyes in a decent impression of Mycroft. "Nonsense. Don't be ridiculous."

"I'm not being ridiculous. I'm filling you in on the details of human interaction that you seem to have missed while growing up in your secluded little cloister with your misanthropic brother."

"You're being ridiculous."

John took a breath as if to speak and then let it out. "You know what, fine. If you want to think that, go ahead. I'm going to get us some takeaway because I'm hungry and you're going to die of malnutrition if you keep this up. And you'd better promise me you'll get your own food after this, because I'm moving out."

Sherlock had been picking idly at his violin strings, but his head snapped up at this. "What? I certainly haven't offended you that badly."

It was John's turn to roll his eyes. "As it turns out, not everything is about you, Sherlock. I'm not moving out to get away from you. (Not that that sounds like such a bad idea, some days.) I'm moving in with Harry. I should have kept a better eye on her after she and Clara split; I don't know what got into me, but it's my fault that she wound up like this and I need to make sure she doesn't overdose again."

"You're being ridiculous again. It's not your fault that your sister poisoned herself. You had nothing to do with it."

"Well, that's the problem, isn't it? I had nothing to do with it—I had nothing to do with her, with her life! If I had, it wouldn't have wound up like this."

"Guilt is counterproductive, John."

"Yeah, well, hopefully something good will come of it. For now, I'm getting food." John shoved his feet into his cast-off shoes and stomped out the door, putting just a bit more force in his steps than usual. If Sherlock were listening (and that was always an "if"), he surely noticed the difference in John's gait.

John returned twenty minutes later with Chinese takeaway and managed to force Sherlock to eat some of it. It was a quiet lunch after Sherlock stopped his protests; perhaps the prospect of John's moving out was weighing on both of them. After clearing the plates (Sherlock should learn to do chores), John went upstairs and packed. It didn't take long—a few shirts, a few pairs of trousers, his underthings, and his laptop were all he really owned and cared about. He came back downstairs with his case to find Sherlock once again ensconced in his chair, holding his violin.

"When will you be back?"

John shrugged. "I don't know. I'll be gone a good while, Sherlock. Months, maybe."

"But what about cases?"

"I know you and Mycroft aren't like most families, but can you take a second and try to wrap your head around the idea that some families care about one another?"

"You've barely spoken to Harry in the past year!"

"Maybe I'm trying to atone for that! Ever thought of atonement, Sherlock? Or regret? Forgiveness? Guilt?"

Sherlock snorted. "Sentiment."

John sighed. "Fine. If you're going to be like this, I'd honestly rather just leave." He picked up his case and trotted down the stairs.

It took a surprising amount of work to look after Harry, work at the surgery, and attempt to run a normal life. During the first few weeks, John did even more cooking than he usually did for Sherlock, while Harry lay in bed much of the time, or else paced and snapped at him. John knew that this was just withdrawal and tried not to hold it against his sister, but, if he'd been hoping that living with someone other than Sherlock would make him feel more appreciated, he had been woefully mistaken.

Somehow, a full month managed to pass without John so much as laying eyes on Sherlock. And then, once again, it was a text that changed things.

Someone's stolen some slugs from the zoo. -SH

Why would anyone steal slugs? How would you even know they were stolen? Couldn't they have just died or crawled away or something? -JW

Their slime is highly valuable—thought to cure diseases. -SH

OK . . . Why are you telling me this? -JW

Care to help me find them? Might be dangerous. -SH

I'm at work. -JW

Meet me at the zoo in 40 minutes. -SH

John typed What part of 'I'm at work' don't you understand? before deleting the message. No sense asking that of Sherlock. The genius simply couldn't fathom that any other kind of work might be of comparable importance to his own. So John made his excuses, cancelled the rest of his appointments for the day, and caught a cab to the zoo. He'd never been able to resist anything labeled Could be dangerous; what was the point in lying to himself?

When John arrived, Sherlock was waiting for him at the zoo entrance. There were no greetings, no words after a month of separation. Sherlock just caught John's eye and tipped his head toward the gate; John followed. A month apart hadn't broken their near-telepathic ability to work together; neither had forgotten the choreography of their cooperation.

Over the next four hours, Sherlock interrogated the head zookeeper, found out who had been working overnight, scanned the security footage, and somehow managed to come up with a culprit whose name John had never heard but who was apparently very active in illegal animal trading. This woman was known for scams and burglaries spanning three continents and was probably no longer in Britain; Sherlock referred the zookeepers to Mycroft and then asked John if he'd be able to have dinner before returning to Harry's.

"I'll pay," Sherlock offered, which was what clinched the deal for John; he'd been picking up as many hours at work as he could—except for today—but still, finances seemed tighter when he was no longer living in Mycroft's large and prosperous shadow.

"All right. Where?"

"I know a place just a few blocks away. We don't need a cab."

John followed Sherlock, as he always did. And then, for the first time that day, Sherlock started to make conversation: "How was that four hours?"

"I don't know. It felt so much shorter." John scratched the back of his head awkwardly. "We should see each other again sometime."

"How about for a lifetime?"

"We tried that already, didn't we?"

Sherlock rolled his eyes. "You really are going to make me spell it out for you, aren't you?"

"Spell what out?"

Sherlock took a small box from his coat pocket and opened it to reveal a ring. "I'm asking you to marry me."

John stopped walking and stared at the jewelry box in Sherlock's hand. It seemed that his legs had stopped working and all the extra energy had gone to putting his brain into overdrive. "Oh my—Sherlock—what?"

Sherlock stopped, too, and he kept glancing from John's face to his own feet. "You said families care about each other. Husbands are family, aren't they?"

"Are you doing this because you want me to move back in?"

"That's obviously a factor."

"Because I can live with you without marrying you."

"Then why don't you?"

"Because my sister needs me!"

"I need you too!"

"Oh, God, Sherlock, have you—"

"No. But I'm . . . less, without you."

John thought back to the monotonous days he'd spent this past month, going from Harry's flat to work and back. Days when the largest dose of unpredictability he'd gotten was about whether Harry would be pacing or moping when he returned. Days when the patients were inane and endless and thought they had rare diseases when all they really had were colds. Days when the only blood he saw was in a vial or a syringe. Days when nothing was labeled Could be dangerous.

"I'm less without you, too."

Sherlock nodded. "Meet me next week at the courthouse. Mrs. Hudson and Molly can be our witnesses."

"Hang on, I didn't say I'd marry you!"

"But that's the only reasonable thing to do, isn't it, when we're both less without each other?"

"No!"

Sherlock nodded once, sharply, and began walking away.

"Hang on!" John called again. "I didn't say I wouldn't . . . Christ, Sherlock, give me a minute here. You shocked me—I don't even know what's happening." He took a deep breath and then started over. Sherlock had stopped walking and was watching him warily. "Another two months. Give me two months to get things sorted with Harry and to figure out what I want. And then I'll move back in. That much I promise. I'll let you know about the other thing as soon as possible."

Two months later, it ended, as did many things concerning Sherlock, with a text.

Looks like I've got a serial killer. Care to have a look? -GL

Can't. I'm getting married. I'll check in this afternoon. -SH

Married?! -GL

Do pay attention, Lestrade. Molly and I were making arrangements right in front of you last week. -SH

Wait, Molly?! -GL

She's a witness. I'm marrying John. Obviously. -SH

Oh. Good. It's about time. Where's he been lately, anyway? I thought maybe you two had a falling out. -GL

He had to take care of his sister. He's moving back in now. -SH

Well, I wish you the best. -GL

Obviously. -SH

And it was the best.