It's a warm August morning in 1926 Los Angeles, California. Mercedes Louise Allcutt (Mercy to her friends) is thrilled to be going to her job as secretary to private investigator Ernie Templeton - until she opens the door and discovers her mother on the doorstep. Known to her friends as Honoria and her daughters as The Wrath of God, Mrs. Allcutt is the very last person earth whom Mercy wants to see, barring a couple of coldblooded murderers she's met in the past few weeks.

But that's only the beginning of Mercy's latest adventure. Add a couple of phony spiritualists, a Hollywoodland gossip columnist who gets bumped off during a seance, a semi-famous starlet, and several other colorful characters, and Mercy Manages to find herself in very deep waters indeed.