221B, for Sherlock, was a cage. Yes, it could be home, when John or a case was distracting, but most days, the flat was suffocating. Stagnant. Walls bound up his mind as much as his body. The only reason he didn't often leave was because, just down those stairs and out that door, there were people.

John knew this well and tried—more often than he'd admit—to get Sherlock fresh air. It rarely worked unless he made a very specific, planned argument.

"Let's go out, hmm?"

"No, don't bother."

"Well, I for one am bored. Maybe I'll invite Mycroft over."

They were out the door in less than two minutes.

Sometimes they would go to Speedy's, or the morgue, but the weather was perfect and the park was a few minutes' walk away. Sherlock agreed, only on the terms of being able to read pedestrians who walked by. The doctor quickly agreed, knowing he'd do so either way.

"Gay," Sherlock said before they'd sat down. John sighed; the park was teaming with parents playing with giggling children, couples joining arm with arm, and old men feeding demanding squirrels. A picture perfect day would quickly, he knew, turn into a show.

"Cheating."

"You can do that all you'd like, but I had hoped we'd also carry on a conversation."

Sherlock reached for his absent scarf and pretended to crease his shirt when it wasn't there. He looked over at John and ignored the amused grin. "Go on, then." He looked away for a moment. "Lawyer. A pretty poor one, too, I'd bet."

"I think it may be best if we sat out a few cases," John said, looking the other direction at several birds chasing one another.

Sherlock waited until he received eye contact. "Why? I've been doing well."

John debated bringing up Adler but decided against it. "I don't know. We just haven't stopped, you know. I thought a vacation might be good. And we're doing well, financially speaking. I figured—"

"I've never taken a vacation in my life, John. I don't plan on it now." Sherlock cleared his throat, considering bringing up the fact that John wouldn't bring up Adler—which was what this was clearly about—but decided against it. "Besides, it sounds awfully boring."

John dropped it. "See that couple over there? Explain." He pointed to a man, probably in his thirties, and a woman, a few years younger, sitting near an oak tree. John couldn't tell what, exactly, was going on, but Sherlock's skill had long ago served his curiosity. No longer did he have to wonder; he could know.

"There?" Sherlock frowned and watched the couple for a few seconds. He didn't mind the challenges. Deducing from a distance was…well, not boring. "Dating, obviously. I'd say for about, oh, three months, going by her sweater." John would have asked for an explanation, but he knew better than to interrupt. Besides, Sherlock was starting to enjoy teaching him. "It's his. Only new lovers do that, typically. They're not exactly fighting; you understand. She's mad…no, disappointed. No! It's grief." Sherlock smiled. "She's lost someone close to her. Maybe just a job, but I'd bet a person."

The doctor and detective watched as the couple's gestures became more pronounced, the girl shied away, began crying, and hugs were exchanged. Sherlock sighed and turned away.

"What's wrong?"

"Nothing." Sherlock began looking for a new specimen. "See over there? Purple hat? Mother of five."

"No, but…we weren't finished with the couple."

He rolled his eyes and let himself lean on the back of the park bench. "I don't understand."

John's ears perked. "The great Sherlock Holmes doesn't understand something?"

"Oh shut up. I doubt you do either. Why do people do that?"

"Do what?"

"That."

"You…you mean hug?"

Sherlock cringed at the word.

"Oh knock it off, won't you? I know you pretend not to have a heart, but be rational. You know what a hug is."

"Of course I know what it is. That doesn't mean I have to understand it."

John bit his lip, holding back sarcasm. Sherlock truly wanted to understand; for once, the doctor would be the teacher. "Alright, you're right. Now look. It's…well…" How to describe a hug? "When you embrace someone, you know…like that…you're vulnerable. They can feel you. Smell you. Hurt you, even. But they don't because it's not violent; it's trust. It's one person saying to the other, 'Yes, I care about you, I'm here for you.' It's letting your physical body be a sort of assurance." John cleared his throat, aware he was rambling. "I don't know. Being in someone's arms, they're the only thing that can hurt you. But they won't. So, really, it's the safest thing in the world."

Sherlock studied John for a moment and looked away. "How do you…um…how do you do it?"

"What, you've never been hugged before?"

Sherlock looked back many years to remember the last time—was it when he was nineteen, when Mycroft…well, when Mycroft was there?—but he said nothing and didn't look at John.

"Right, I mean…it's fine." John cleared his throat again and looked around, suddenly feeling rather awkward. "Well, one person puts his arms around the other—"

Sherlock turned around sharply. "How?"

John swallowed, thought a moment, and stood. Sherlock's eyebrows shot up and his eyes filled with terror, but John motioned with his head for him to stand. Sherlock did, hesitantly, and looked at the doctor intensely.

"I don't know how."

"It's fine."

"We're in public."

"Sherlock."

John put out his arms and waited. Sherlock stared as though a two-headed snake had just landed in front of him. But John waited.

Sherlock looked around. No one was paying much attention. He looked at John and took a step forward. Then another. He put his arms around John, and John put his arms around him. The doctor's head lay perfectly on the detective's chest; he could feel a small puh-puh, puh-puh of his heart.

Sherlock could feel John's heartbeat, too, and it scared him. Because one day that heart would stop beating, and then…then who was there to get him through the day? He tried to let go of the thought when he felt the doctor's warmth and, really, when he felt how relaxed John was. He realized how tense his body was and tried to relax his own, but the thought of John's heart…well, it was too much.

He pulled away quickly; John nearly fell but caught himself, noticing the tears in Sherlock's eyes.

"I'm sorry," Sherlock said, already walking back to 221B. He belonged in the cage. "I'm not good at this, either."

John didn't go home, at first. Sherlock was a man of space. When he did return, the lights were off and he heard the soft murmur of the shower.

He placed his keys on the table and knocked on the bathroom door. "Sherlock, I'm home. You okay?" No answer. But that was expected. He went to the kitchen, starving and looking for a distraction.

When John returned to the living room, the shower was still running. Yet a soaking wet detective, wearing only a deep purple towel, suddenly clung to his body as though life itself depended upon it.

"Is this right?" Sherlock asked.

John smiled and hugged his best friend back. How many years of abuse, neglect, and mockery had this man gone through before anyone cared enough to show acceptance, compassion? And how lucky was he, John Watson, to be the man to show the great Sherlock Holmes care?

"Yes," he said, letting his face touch the white, damp chest. "Yes, that's just fine."