The Missing Madonna is the third book in the Sister Mary Helen Mystery Series. A convention with the OWLs (Older Women's League) takes place in NYC. Sister Mary Helen and Sister Eileen join their friends in various workshops and lectures. However, Sister Mary Helen soon becomes more focused on finding out why Erma Duran is upset and secretive. The book continues with their return to San Francisco and the sudden disappearance of Erma. Sister Mary Helen and Sister Eileen investigate the disappearance, even when told not to, with the help of her landlord, the police and the remaining members of the OWL's. The story was a light, fluffy story. I love the Sister Mary Helen Mysteries but felt this book went round in circles more than the first two books. However, if you like light mystery fiction with a bit of Catholic humor mixed in, you'll most likely enjoy The Missing Madonna.