Winter has come early to the tiny Siberian village of Roslazny, but for Olga Pushkin, aspiring writer and Railway Engineer (Second Class), it only makes leaving the harder. Olga is being forced overseas by her jealous superior, and now faces two years in exile from her beloved rail-side hut, her white-breasted hedgehog Dmitri, and Vassily Marushkin, sergeant-in-charge at the tiny Roslazny police station. Fate seems to intervene when Olga’s train crashes outside Roslazny, shutting the line and killing two on board – local celebrity Danyl Petrovich and his wife, Anoushka. But Vassily Marushkin soon discovers that the Trans-Siberian locomotive was derailed on purpose. As the weather closes in, trapping the villagers – and the suspects – inside, Vassily begins a murder investigation in which Olga and her long-lost friend, Nevena Komarov, soon become closely involved.