When an affluent railcar owner disappears with millions of dollars belonging to Moose County investors, the international police launch an intense investigation to find the fugitive. But journalist detective Jim Qwilleran and his feline crime-busters find a mystery to unravel that is closer to home: Who blew the whistle on the embezzler—and why? Qwill goes full steam ahead to solve the puzzle before tragedy occurs, but the case is complicated by a train wreck on the main line and a murder in a railroad tavern. With the help of Koko and Yum Yum, Qwill is about to prove that the police are on the wrong track.