Sister Mary Helen is puzzled when her friend Erma fails to call. After checking Erma's empty apartment, she begins investigating.

Sister Mary Helen investigates the murder of a homeless woman behind the nun's shelter.

Sister Mary Helen is in luck, depending on how you look at it. She and Sister Eileen are in Ireland to attend the weeklong Oyster Festival in the little village of Ballyclarin. They make their first stop at a central oasis of food and drink called the Monks' Table. Mary Helen overhears a woman saying to the man with her, "I am surprised someone hasn't killed you already." But Eileen assures her that it's only a way of speaking, and Mary Helen is relieved--until...