Michael Shayne accepts an assignment to investigate a gang of pari-mutual race tickets counterfeiters over the protests of his secretary, Phyllis Hamilton, who wants him to join her on a vacation. Shayne contacts Mayme Martin who offers him information, and sends his friend Tim Rourke to get it. Tim arrives to find Inspector Rafferty there as Mayme has been murdered. Shayne has gone to the race track to see Jim Payson and Al Hardeman, the operators. Two thugs, Joe and Punk, take shots at Shayne and he is wounded. He later learns that a printer, Madden and his engraving foreman Edwards served time for counterfeiting Irish sweepstake tickets and Shayne thinks he has the case solved... until Madden and Edwards turn up murdered.