"I did save him," Castiel said, with a sharpness he had not possessed the entirety of the day. "He is here. He is safe..." He trailed off. It wasn't just safety he was supposed to be insuring. His purpose was higher. God's purpose.
Who was to say Fred was not his purpose? He stood up, but rather than taking a step or moving, he just stood, and looked down at her reaching for her books. No, Fred didn't need him. Not really.
He reached out a hand and touched her hair, brushing it over the back of her neck. There was an ozone sharpening, a harsh push of air in the stillness of the room, and the space where he had been was empty.