King, a German shepherd, is heir to a fortune, and Ellen (Peggy Dow) administers his inheritance. Then King is murdered (poison). Ellen is judged to be responsible.
Then things get fantastic. The scene is Beastatory, an animal heaven, where King asks an animal jury to allow him to return to earth, investigate the crime, and expose the real killer. He gets what he asks for, and he's reincarnated as Rex Shepard, private-eye (Dick Powell). Rex is accompanied by Goldie (Joyce Holden), formerly a palomino and now Rex's secretary. If you think Rex solves the mystery, you're right, but that's all I have to say. The rest you should discover for yourself, assuming you can ever find a copy or catch it on TV.
Well, I can't resist a remark about the costuming. It's just great, particularly Goldie's hat and shoes. I'd love to see this one again, but I don't think it's available on DVD.
Okay, one more thing. That last scene. Gets me every time, even thinking about it.