A puzzling locked-room mystery that puts someone Oldroyd loves in terrible danger... When a film shoot on Wharfedale's vintage railway turns into a grisly crime scene, DCI Oldroyd's idyllic visit to the countryside with his partner Deborah is well and truly stopped in its tracks. One of the film's stars has been shot dead in a train carriage while the cameras rolled outside. But nobody else went in-or came out. Has the killer really pulled off the perfect, impossible crime? Scouring the victim's past for clues, Oldroyd soon unearths a string of heartbroken lovers and a mountain of unpaid debts, each adding to the growing list of suspects. But before he can determine who the culprit is, there's the small matter of figuring out how they did it. A potential connection to a previous tragedy offers Oldroyd a much-needed lead... Whoever the perpetrator is, they are ruthless and determined to avoid detection, and when a railway worker starts joining the dots, they are quickly silenced-for good. But as Oldroyd gets ever closer to the truth, it's only a matter of time before he is given a chilling warning to back off. Perhaps Deborah should have stayed somewhere safe...