Oliver Quade is a pitchman who follows state fairs that feature dog shows---which limits his territory more than a little---at which he sells encyclopedias...and does it well as he possesses a photographic memory that amazes the rubes. The Champion, in the title, is a Great Dane who has won the title at the Rubeville State Fair, and it isn`t long before the Champion turns up dead, which is because somebody---motive unknown at the moment---has killed the Champion. This is repeated at other shows along the way and Quade`s bright young assistant, "Small Fry", fancies himself as an amateur detective, and starts nosing around into the mystery and drags Quade along with him.
