Ever since Sam had cured himself, he really hadn't been feeling great. He hadn't noticed at first, since it was so much better than when he had been infected. However, by the time they were chasing down Cas with Rowena, he was definitely feeling it. Then there was Cas beating the living daylights out of his brother, and Rowena escaped. All in all, there hadn't really been time until they got back to the bunker. Even then, Sam was loathe to bring it up, so he did it in the most low-key way he knew how.

"Hey, I'm gonna hit the hay for a few hours; I'm beat."

He took Dean's glance in his direction as acknowledgement and headed off to his room. Once he reached it and shut the door, Sam allowed himself to collapse on the bed, fully clothed, and just succumb to sleep.

Meanwhile, Dean and Cas were where Sam had left them. Dean was icing his face while Cas just watched him guiltily. Eventually the angel spoke.

"Did Sam seem okay to you?"

That got Dean's attention. He turned toward his friend.

"Yeah, did he not to you?"

"I don't know. He seemed a little off. Did something happen to him?"

Dean opened his mouth to reply, but shut it again as he realized that he didn't know. He had been separated from Sam for days, leaving his brother alone in zombie-land, and hadn't even bothered to see if he was alright. Yeah, he'd asked over the phone, but Sam would never volunteer that kind of information, and Dean knew it. With a groan, he pushed himself up from the table.

"Dean?"

"Come on, we're going to check on my sasquatch of a baby brother."

Together they went to Sam's room, where Dean silently pushed the door open.

Sam was asleep on his bed, but it didn't look like a particularly restful sleep. He was tossing and turning, and his face was flushed. As Dean listened, he realized Sam was muttering, so he stepped closer to hear what he was saying.

"Dean, Dean, come back. I'm scared. What if I don't find a cure in time? Dean!"

"Aw Sammy," Dean sighed. He put a hand on his brother's forehead to confirm what he already knew. Sam had a fever. The touch calmed down the younger man, at least for now.

"Come on, kiddo, you could have told me you felt lousy." Dean remonstrated softly. Then he went back to the doorway where Cas was waiting.

"We'll let him sleep for now. I'll check on him later to make sure he doesn't get worse."

With that, the two of them left and went back to the main room.

Sam woke up freezing. Rationally, he knew he had a fever, but he couldn't really summon the energy to care. He shed his outer shirt and crawled under the covers, but he was still shaking. For a while he just lay there, hoping he would go back to sleep. After about an hour, Sam noticed out of the corner of his eye that the door was opening. Turning his head just slightly, Sam realized that it was Dean.

"Dean," he called.

At that, the door opened all the way and his brother came in and sat down on the bed.

"Hey, how're you doin'?"

"Been better."

Dean snorted. "Understatement of the century, little brother." Taking advantage of the fact that he had Sam awake and aware, he continued. "Did this come from something that happened in zombie-land, or is it just some of the worst timing ever?"

Sam sighed, then decided to just come out with it.

"I think it's left over from the cure."

Dean was confused. "The cure? You found it already? And you tested it on yourself? Come on, you know better than that!"

"I had to, Dean."

"No, you didn't. Find someone else to be the guinea pig, there were plenty around!"

"Dean!" Sam propped himself up on his elbow and looked straight at his brother. "I had to do it, because I was infected, had been infected, and had literally minutes left of lucidity before I became a monster too!"

Dean stopped, just staring at his pale, shivering, feverish, alive, little brother. Sam had been dying, and he hadn't even known. He had been dying because Dean had allowed him to be the distraction.

"Hey," Sam's soft voice pulled him out of his spiraling thoughts. "It's okay; I'm alive. The only thing here is I've got a nasty cold, something we've dealt with a thousand times before. I'm fine."

Dean swallowed hard and nodded.

Satisfied, Sam laid back down and buried himself under the covers. "G'night, Dean."

Dean smiled and ran his fingers through Sam's hair.

"Goodnight, Sammy."