A brilliant swindler, Olivier Parker, hires a small-time pipe salesman, Amédée, to swindle a naive provincial, Ferdinand Galiveau, a chicken merchant. Renamed Teddy Morton and now a jockey, Amédée must ride a mare on which Ferdinand, advised by Parker, must bet. Absolutely convinced of his mystification, Parker bets on an oddball who, of course, loses, while at the last minute Galiveau, having bet on an outsider, wins a fortune. All Parker has to do is find another sucker.