"And Brave Sir Squirrel rode his black palfrey on," Sam whispers, lower, lower, until Dean's eyelids are fluttering closed on his pillow, "until he reached his castle. And all his friends were there, waiting for him, and they had a big feast with lots and lots of food and, er, rootbeer." He waited until Dean's sleep-charged breath answered, smiled, and only then turned his head to the dark-haired shadow with the glass of water.

"I thought you might need this," Castiel whispered, still enunciating every syllable with intent clarity. "He likes your stories better."

Sam drank, pausing to savour the touch of lemon and whiskey. Castiel's tug-of-war with tastebuds was still on, but he'd learnt to make a decent toddy over the weeks Sam had been on storytime fatigues. Dean, an exacting customer, never went to sleep before the sixth or seventh tale.

"But he likes your songs better."

They paused to watch the sleeper, his mouth a sweet ap, his snore still a breath's lullaby.

"We'll find a cure," Castiel said intently, his hand anchoring his promise to Sam's back. Sam felt the room's penumbra blur and closed his eyes on the sting.

"I want to. I hope to. But... is it a sin, that I want this too?"

Dad had trained him to the bone - had taught him that timing was of the essence, in Latin, in lying, in the lethal duress of his guns' recoil. Sam did not miss Cas's pause.

"No," Cas said, and did not move his hand.