"Be an angel to someone else whenever you can, as a way of thanking God for the help your angel has given you."
— The Angels' Little Instruction Book by Eileen Elias Freeman, 1994
The first time Cas accompanies Sam and Dean on a hunt after his fall the brothers book a twin room and a single room. It takes Cas a moment to remember that of course he'll need a room because he sleeps now, and he thinks that he'll be left on his own. But then Dean pushes him into the twin room and Sam leaves them.
"But… Sam," he says as he stands in the middle of the room looking confused. "You always share with Sam."
"Well, tonight I'm sharing with you," Dean says, shrugging as if it's nothing.
So Castiel sits down on one bed but immediately stands back up again. "Which would you prefer—"
"It doesn't matter."
"You usually take the one on this side. I'll take the other."
"Cas—"
"It's fine, Dean."
Later that night, once they've showered and eaten, Cas feels edgy. Dean's looking through the police files they picked up on their way into town and Cas watches TV until it's late and his eyelids are drooping and he can't stop yawning, but still he doesn't go to bed.
"You should sleep, man," Dean says eventually.
"I'm not tired," Castiel tells him. And it's a lie, because what he doesn't tell Dean is that now he's human he dreams. Although nightmares would be a better work to describe it, because he dreams about his brothers and sisters falling, only he's the one pushing each and every one out of Heaven and watching them burn on the way down.
"Cas, go to bed. Sleep."
"I don't want to sleep," he says, and it's the closest he'll come to admitting his new found weakness.
Dean puts the TV off and moves him over to the bed, stripping him down to his boxers before tucking him in, and Cas is so tired that he can't stop him so he just lets Dean get on with it.
"I'll watch over you," Dean promises in an ironic reversal of roles as Cas's treacherous eyelids fall shut against his will.
Dean's words are the last thing he remembers hearing as he falls into the first dreamless night's sleep he's had in his new human life.
