It's all aboard! for mystery when Dinah Galloway takes the cross-country train from Vancouver to Toronto, to appear on a TV talent show. But will she make it-or be permanently derailed? Along with her sister Madge, and her fellow junior musicians, tree fanatic Pantelli Audia and history buff Talbot St. John, Dinah is shadowed by someone who wants to get hold of an $80,000 treasure left by her late dad. But what is the treasure? The redheaded, singing sleuth realizes that the secret dwells somewhere in her dad's murky past, and involves a funny, if less than respectable, ex-con named Ardle McBean, and a mysterious man with a bowl cut. The mystery accelerates when Dinah's sweet, elderly piano teacher, also on the train, disappears and the danger to Dinah increases. She struggles to keep on the tracks of the mystery before the shadows, past and present, overwhelm her.