Recently retired Met Detective Roz Parker boards the Christmas Eve sleeper to head home for the holidays, anxious and dreading her new role as grandmother upon arrival. Violently thrown from her thoughts when the train derails, Roz finds herself stranded on the snowy tracks, where she finds a fellow passenger suspiciously murdered in a locked cabin. With the train stuck in snow in the middle of nowhere, a killer stalks its carriages, picking off passengers one by one. Unexpected alliances emerge as the passengers realize that those who sleep on the sleeper train may never wake again. Can Roz identify the killer before anyone else is lost? And will she have to miss the birth of her first grandchild to solve the mystery? All aboard for...Murder on the Christmas Express!