Gun, with Occasional Music

Conrad Metcalf has problems. He has a monkey on his back, a rabbit in his waiting room, and a trigger-happy kangaroo on his tail. (Maybe evolution therapy is not such a good idea.)
He's been shadowing Celeste, the wife of an affluent Oakland urologist. Maybe falling in love with her a little at the same time. When the doctor turns up dead, Metcalf finds himself caught in a crossfire between the boys from the Inquisitor's Office and gangsters who operate out of the back room of the Fickle Muse.
Jonathan Lethem's first novel is a science fiction mystery. It's funny. It's not so funny.