Drama-documentary examining the death of banker Thomas Briggs in July 1864, which was the first murder to be committed on a British train. The film uses testimonies from court transcripts, memoirs, letters and newspaper reports to tell the story of the crime through those connected to it, including engine driver Alfred Ekin - who found the body - and Richard Tanner, the detective in charge of the investigation. It also explores the huge public outcry and debate it provoked. Narrated by Toby Jones