Based on Émile Zola's 1890 novel "La Bête humaine", and set during the Blitz, Ruben Roberts (David Suchet), a railway official, discovers that his wife Selina (Saskia Reeves) was sexually abused as a child by the Chairman of the Line, Arthur Grandridge (David Belcher), her godfather. Ruben hatches a plot to exact revenge upon Grandridge on the Brighton Express.