When a band of homeless people cremate a beloved dog in San Francisco's Golden Gate Park, the authorities are willing to overlook a few broken regulations. But three weeks later, when the dog's owner gets the same fiery send-off, the San Francisco Police Department has a real headache on its hands. The autopsy suggests homicide, but Inspector Kate Martinelli and her partner, Al Hawkin, have little else to go on: a homeless victim with no positive ID, a group of witnesses with little love for the cops, and a possible suspect, known only as Brother Erasmus, who proves both articulate and impossible to understand.

Erasmus, has a genius for blending with his surroundings, yet he stands out wherever he goes. He is by no means crazy--but he is a Fool. Kate begins the frustrating task of interrogating a man who communicates only through quotations. In Laurie R. King's To Play the Fool, trying to learn something of his history leads Kate along a twisting road to a disbanded cult, long-buried secrets, the thirst for spirituality, and the hunger for bloody vengeance.