Castiel didn't meet her gaze. "I apologize for being unable to explain in person. There were... circumstances that prevented me from being here." Too many events were in progress. The creatures being called by the Hellmouth had expected resistance, and the angels were being overworked to keep things in check. He himself was being drawn into conflict after conflict, and nearly hadn't gotten here in time.
At her question, his shoulders deflated slightly. "I am not certain. The source of this is hidden from me. When I sought a solution, only the path containing your presence could save both your parents." He reached into the pocket of his coat, and drew out an amulet on a black strip of old leather.
"This belonged to your father, long ago for you, not so long ago for him." He offered it to Ellen. "It was a gift to him, from Sam."