Instead of answering her question, Castiel did exactly as he'd intended to do and appeared behind her, grabbing the arm with the blade in it and twisting her around until the blade fell into his hand.
She was light, warm...he probably should have let go, but for some reason, he couldn't bring himself to do anything other than shove her away. He should have pressed his hand to her forehead, smote her, made certain she'd be gone, but...she hadn't tasted like ashes.
"How I got here is of no concern to you," he replied. "You presumably honoured the agreement Sam and Dean made with you. Our association is done."