Perseus and Andromeda

Acrisius could not see it, but there was a thin opening in the rock in front of the Priestess, and something like white smoke was coming out of it. It was the message Apollo was sending her. The Priestess listened to the smoke as it moved past her, and she waited until it left before she spoke. "The only child you and your wife will have is the one you have now. You will not have a son, but your daughter will. You must be careful of this child because one day he will kill you." "My daughters son? But why? How can I stop this from happening?"