Thirteen-year-old Flinn Nachtigall lives with her mother and three half-siblings at the abandoned train station in Weidenborstel, a desolate little place somewhere in northern Germany. She misses her favorite brother Jonte, who disappeared two years ago: a postcard that arrived shortly after Jonte's disappearance is all that remains of him. But why does Flinn recognize an old train on it, while her family only sees a rusty handcar? Flinn finds no peace. Night after night, she waits at the abandoned station where Jonte was last seen, dreaming of a reunion, until one evening a train rolls in, pulled by a massive, smoke-belching locomotive - the train from Jonte's postcard! Magically drawn to a ghostly creature, Flinn jumps onto the departing train and plunges as a stowaway into the adventure of her life.