Set entirely on the London Tube, a young couple, Tom and Alexandra, take the train home. They begin to talk to a fellow passenger, a former soldier named Peter. They discuss life in London, ambitions and the couple's relationship. Peter is struggling to find his place in society again having returned from duty, and the couple become a little unnerved by his conversation. Trapped on the Underground until they reach they're destination, they are forced to make a decision, the consequences of which will haunt them forever. PASSENGER draws upon the experiences of soldiers returning from service and aligns them with the views of people who have never had to experience such a hardship as war.