SPOILER WHO CARES ...so Delia was already a xxxxx?
at the end, when he comes back to Delia's house, the witches are there singing the "witches song" which he heard at the beginning of the movie when he took Delia home and was waiting for her in the car.
So, was this a premonition, or was she already a witch (at the movie beginning) ? Lots of other questions, of course.