For a while, Dean thought it was just the fact that his brother was just that much of a nerd, that he'd rather sleep on the couch in the library than pick a room and settle in. He seemed just as thrilled as Dean about the bedroom setup. He acted like it, anyway. He made a big show about inspecting each one and then finally claiming the one across from Dean's, tossing his bag down on the bed with a satisfying thump and heading back out to the library while Dean set about reorganizing his space with the giddy enthusiasm of a ten-year-old.

He wasn't a bit surprised that Sam fell asleep over a pile of books at the library table that first night. It was a little bit adorable, actually. When he found Sam the next morning, with his head resting on his outstretched arm and his long hair splayed over the pages of whatever book he'd been so interested in, it took him back to all those nights they'd spent at Bobby's when they were kids. Sam had never stopped being that same kid who could get so obsessed with something that he forgot to eat or sleep.

Dean was glad he never had that problem. He stretched lazily in his dead guy's robe and scratched his stomach, thinking he could probably get Sam away from the books if he made breakfast. Even Sam wasn't such a little freak that he didn't love the smell of bacon.

Sam ate, and he seemed perfectly happy. They talked about how nice it was to finally have a home, to feel settled. And then Dean watched, dumbfounded, as Sam pulled a pair of clean clothes out of his duffle, showered and changed, and went straight back to the library.

His bag still sat where it had landed in the middle of his made bed, fully packed.

After a couple of nights, Dean really started to wonder if there was something more than an obsession with the books going on. His own room was starting to feel like his, and when he'd shown it off to Sam he'd felt a surge of pride at seeing all his guns and records displayed around him. His space, all his. It was something he'd never had before. Sam, like the annoying little shit that he was, wadded up a gum wrapper and tossed it at his trash can, littering up his floor. Like he just didn't get it at all.

"Really?" Dean demanded.

Chagrined, Sam retrieved the wrapper and put the damn thing where it belonged, even though Dean got the sense he was rolling his eyes the whole time. Then he buried himself in the books again.

By the fourth night, Dean decided Sam needed an intervention to pull him away from the books. He wandered into the library and announced his presence by sitting down noisily in the leather chair he liked best. Sam glanced up at him, and then flipped a page, returning his attention to it.

"Anything good?" Dean ventured.

Sam raised his eyebrows, looking from one open book to the next. He had several spread out on the table in front of him. "Uh, yeah, actually. There's a lot here."

Dean thought about pretending to be interested, but instead cut right to the chase. "Hey, so, you're definitely sticking with the room across from mine, right?"

"I guess so. That a problem?"

"No. That's great. I just, wasn't sure. Because your duffle is still sitting in the middle of your bed, the one you haven't actually slept in yet."

Sam's eyes darted back to the book nearest him, and he seemed to cringe from the accusation in Dean's tone. He shrugged. "I will. Give me a break, Dean. I mean, we've never even heard of half the information collected here. It's-"

"Hey, I know. Believe me." Dean held up a hand. "I'm not trying to tell you not to geek out."

Sam smirked.

"Just, it feels good, you know? Finally having a room. Getting things the way you like 'em. Pictures on the walls. I'm a grown-ass man, Sam, and I've never had my own room. Hell, I've never had a bed that was mine."

This time, only one side of Sam's mouth crooked up, making his smile look wistful. "Yeah, you said that," he said.

Dean caught the edge to his tone. "Okay, what's wrong?"

"Nothing, Dean."

"Sam, seriously. What? Do you not want to stay here, is that it?"

"No, you said it yourself. This place is perfect."

"Perfect, except that you want to live in the library."

"It's not that."

"Then why won't you unpack?"

Sam met Dean's gaze then, his eyes piercing and hard, his fingers poised on the edge of a page in mid-turn. "Unpack what?" he asked in a clipped tone. And then he pressed his lips together and refocused his full attention on the page.

Dean opened his mouth to answer, and then frowned, closing it again. They traveled light, sure, but his brother owned things, he was sure of it. Wasn't he? He racked his brain to recall Sam's possessions, and if things had been lost over the years, he struggled to remember what they had been. What had Sam owned? What did he value? What defined him?

He kept coming back to the little brother who had only ever wanted to fit in, no matter where they went, so much so that every possession, every thing, article of clothing, every facet of his personality seemed like a carefully constructed mask of normalcy. From the sports heros he supposedly idolized to the popular music he listened to, Sam blended. He had always been what he wanted other people to see. A chameleon. He had always been so terrified of letting people see who or what he really was that he'd created a front for himself.

And without that, what did he have?

A worn duffle bag of second-hand clothes. That was the extent of Sam's mark on the world, this world he had saved.

"Sam..." Dean started to say.

"I'm sorry. I'll... I'll get to it. I will. Just... later, okay?" He didn't look up,

Dean sighed, feeling defeated. "Fine. Okay." He stood up and hesitated a moment, then headed back to the hallway toward his room. He paused at the door, looking in, looking over his guns, knives, records, at his photo of Mom. Then he walked past it to Sam's room.

The night dragged on, and when he felt it getting late, he headed back to the library, not surprised to find Sam in much the same position he'd left him, still reading.

"You're gonna give yourself an aneurysm," he informed his brother.

"I don't think it works that way."

"Come to bed, Sam."

It was a plea. A plea to let there be some form of stability in their lives, and Sam knew it. Sam looked up at him, relenting, his shoulders sagging a bit, and he sighed. "Yeah, okay."

He pushed back from the table and stretched, planting both hands in the small of his back and arching it to release the stiffness, then followed Dean down the hall toward their bedrooms. He blinked away the filmy grit of weariness from his eyes as he walked, his eyes on Dean's feet ahead of him.

Sam put a hand on the door frame to his room, and then looked up in surprise when Dean took hold of his arm and led him on further down the hall through the doorway to Dean's room.

Sam frowned at the sight of his own duffle on Dean's bed. "Why did you...?"

Dean shrugged. " Stay with me? Just for a while."

"But…" Sam's brow was still wrinkled in confusion. "It's not that big a bed, Dean. I thought you liked having your own room."

"I do," he answered, encouraged because Sam hadn't actually said no to the idea. "And you will too. But right now… You know, we slept in the same motel room our whole lives. Hell, the same bed when we had to."

Sam laughed, once. "Tell me about it. You always stole the blanket."

"That's—that was self-defense, okay? Look, at least we don't have to share blankets. You can have your own blanket. But... I mean, I know this doesn't fix the problem. You still need to spruce up your room and all. Sam, I want you to. You deserve your own space, your own stuff, you know? But until you do..."

"Thanks," he said. "Dean, thanks. I mean it. You're sure about this, though?"

"Look." Dean took hold of Sam's shoulders and pushed him down onto the memory foam. Then he sat down beside Sam and scooted back toward the headboard, motioning for Sam to join him. When Sam did, he wrapped his arm around his younger but not smaller brother, pulling him closer than he had dared in so long, the space between them instantly vanishing. Sam exhaled and leaned sideways into him, bringing back memories of shared motel beds and anxieties that Dean had been able to erase just by holding his little brother close.

Dean went on, reassuringly. "This is temporary. You've always been the one who went after what you wanted. You'll figure this out. Sam. Just… go easy on yourself, okay? You've been through more shit than most people see in ten lifetimes. We both have."

Sam leaned his head back against the headboard and closed his eyes, the base of his head resting against Dean's arm. "Yeah," he admitted. "You know, now that I think about it. The Men of Letters had some pretty cool astronomy charts in one of the binders I found. I could get those blown up to poster size to put on my wall."

Dean grinned. "That sounds perfect. Nerdy. But perfect."

"Not weird?" he turned his head toward Dean, squinting his eyes uncertainly.

"No. Perfect. It's a very Sam thing," Dean said definitively.

Sam nodded, looking up to study the ceiling of Dean's room. After another moment, he said, "What else?"

"Hmm?"

"What else would be? You know…a 'Sam' thing?"

Dean almost laughed, but he caught himself as soon as he realized Sam wasn't joking. Sam wasn't looking at him, but he had that sincerely pensive expression on his face that he got when he was taking himself and everything else too seriously.

"Well, your ability to spring chick-flick moments on me, for one," he said, rewarded with a grin from Sam.

And then he found himself launching into a dissertation on everything Sam. Sam's quirky little likes and dislikes, the way his voice cracked when he got really annoyed, the things he ate and wore and worried about. The type of girl he was most likely to check out and where he was likely to take her on a date and what they were likely to do. Which bones he had broken and which thumbnail he chewed and where he kept that worn picture of Jess, and the fact that talking about her still made him tear up.

Dean stopped, worried that he was making Sam uncomfortable, because maybe it was weird to be that aware of another human being. But Sam just looked at him and smiled, at bit gratefully.

It wasn't weird, he realized. Any more than it was for Sam to have followed him around from the time he was old enough to stand. Sam had grown up mimicking the things he said, the way he dressed, the albums he'd listened to, the sit-coms he'd watched. Sam was likely as much an expert on him as he was on Sam.

"Thanks," Sam said. "For knowing me."

"Anytime, little brother," he said.