The big news story that comes out of this jaunty documentary is that it apparently reveals the long-shrouded identity of the inside man, AKA the Ulsterman, who helped make the Great Train Robbery of 1963 possible. The heist netted £2.6m for its 15 participants, some of whom, including Buster Edwards and Ronnie Biggs, went on to become household names. While it’s interesting to learn the identity of the post-office worker who tipped off the thieves, the real star of the show is the chap, one of the robbery’s masterminds, Gordon Goody, who’s come forward after 51 years to name him. Now a sprightly 84-year-old living in Spain, Goody is a wry, salty raconteur, revealing his own life story as well as his recollections of the robbery with disarming frankness. Harry Macqueen plays a younger version of Goody in reconstructed sections, while neatly edited archive material builds a sense of the period. It’s a bit televisual for cinematic release, but absorbing viewing all the same.