Cas exhaled. "When an angel's wings are injured," he said to his feet, "the healing process can be augmented by… grooming, I suppose, would be the most accurate word. Removal of the maimed feathers to allow growth of healthy ones. Otherwise, they're left to fall out alone." He tilted his head towards the nightstand. "As you see."

Dean stared at him. "So… that's why I can't help?" he said slowly. "'Cause I can't, y'know… see 'em? Or touch 'em?"

"Yes," Cas said, slightly too quickly, and Dean snorted.

"You're still a shitty liar, Cas," he informed him. "What ain't you tellin' me?"