A body is found face down in a tank. Detective Inspector Iverson, investigating what seems like a routine case of suicide, becomes involved with the mesmerizing psychotherapist who was helping the dead woman find her true self. Gradually their roles are reversed as her probing uncovers the detective's own deeper motives and needs, until the knife-edge between suicide and murder is exposed.

The wise-cracking Fitz is a brilliant but flawed criminal psychologist with a remarkable insight into the criminal mind.