He doesn't need the spell to believe his brother. Dean is sure that there's another way and that's enough for Sam to believe him. Right now he doesn't see a way out, doesn't see a way that won't end in blood and pain and leave him alone again.

His hands twist in his shirt as he shakes, awkwardly curled up in his lap as the tremors take him. "Hurts," he pants, trying to get even closer. "God Dean, it hurts."