Down-on-his-luck Alpha Trax Conductor (rail) Joe Griffin (Ed Speleers) arrives at Waterloo Station in time to start his shift on one of the Caledonian Sleeper passenger train, which is scheduled to depart London at midnight under a full moon. A group of passengers is introduced, consisting of Kate (Shauna Macdonald), Adrian (Elliot Cowan), Matthew (Amit Shah), Billy (Sam Gittens), Nina (Rosie Day), Paul (Calvin Dean) and Ged (Duncan Preston) and his wife Jenny (Ania Marson). While he checks the passengers for tickets, he meets his unrequited love, the tea-trolley girl, Ellen (Holly Weston), who consoles him for being turned down for a promotion. An hour after departure, the train is travelling through a remote and forested part of the English countryside, in a Mobile phone signal#Dead zones. Here the train is forced to undergo an Emergency brake (train) to prevent a derailment when a deer runs onto the line.