Many years ago, a mother made a promise to give her first born son in marriage to Hecate in exchange for money and power. Now Hecate is back to claim her husband, because only in a sanctified marriage can she conceive and give birth to a full demon child. The son is being forced into the marriage under a spell, and his beloved original fiancée has been banished. Piper is catering the wedding with help from Prue. A priest tries to vanquish the demon but fails and is killed for his trouble. When the priest falls out a second story window, Andy takes the sword he was carrying to Prue to find out where it's from. Phoebe thinks Piper might be pregnant with a demon child because of a premonition. Finally the three sisters compare notes, realize what is going on, and stop the wedding just in time.