When Eliot Ness and Agent Martin Flaherty raid a small butcher shop looking for illegal liquor, they find more than cheap booze: they find the body of the store's owner, Arturo Vittorini, in the meat locker. The dead man's wife Barbara accuses the neighborhood Mafia chief, Joe Bucco, of ordering the killing. Bucco denies having anything to do with it - the dead man was his wife's cousin - but is pretty sure his collector, Little Charlie Sebastino, is responsible. 

The team faces a new kind of criminal when they battle the owner of the swank Jockey Club, a respectable gent who is the boss of the St. Louis underworld.