A/N: Set in a very slight AU where Sam stopped Cas from doing the Really Stupid Thing at the end, thus sparing Claire from further trauma. Part 1 of a series I was hoping to have written in full during the hiatus, but appear to have failed already.
Prologue - Castiel
There was going to be hell to pay when Dean woke up and found out. Possibly literally, knowing their lives.
This time it would be an argument about the frivolous use of grace: Cas had sent both Claire and Dean off to sleep. He had deemed it to be necessary, indeed essential in Dean's case, but Dean wouldn't see it that way. Especially if he found out just how difficult it had been to knock him out completely: the Mark of Cain was taking its toll once more, transforming Dean into something other than simply human. Something he was glad Sam had stopped him from allowing Claire to see, because she certainly did not need any further trauma adding to her nightmares.
"Cas?" Sam's voice sounded small, hopeless. "Dean's not okay, is he?"
Cas knew this was one of the occasions he would be expected to lie. He knew there were benefits to lying, and at times like this, Sam was seeking comfort rather than honesty. Or he would be, were he asking anyone human. Cas was honest: he had lied to Sam and Dean once, and it had cost him dearly. He had vowed never to do it again.
"No," he said regretfully. "But we will find a way to help him, Sam. I…"
He found there was an uncomfortable lump in his throat. This was something he had experienced a few times during his time as a human: when he had been forced to kill his sister and brothers; when Dean had thrown him from the bunker; when Sam had shunned him at the bar in Wyoming. It was not something he had ever expected to feel as an angel.
"I cannot lose him again," he admitted once he was able to speak again.
Sam stretched a hand into the back seat and squeezed Cas' arm tightly. Their eyes locked in the rear view in a moment of complete understanding. They both loved Dean; they both needed him to survive. Because, without him, there was nothing left in this world for either of them.