[1][2][3] Carl Matthews (David Morrissey) commutes by train to London where he works in a property management office under a boss who is pressuring him to dismiss an employee.

He has a kind and supportive wife Maggie (Olivia Colman) and two teenage children who he feels do not appreciate him.

One morning he complains to a woman called Sally (Sheridan Smith) that she has taken his seat on the train.

He later apologises to her and they start chatting, a relationship develops and she reveals that she is divorced but about to marry again, although scenes with her fiancé (Sean Maguire) suggest she is going cold on the idea.

[5] Filming took place on the South West Trains network, including London Waterloo station.