The film has an engaging group of performers, a fast-moving locomotive, and some unpleasant Nazis – and manages to fill 90 minutes in a pleasant way. It falls to the main policeman, Gordon Harker, along with his eager but inept partner "Bingham," played by Alastair Sim, to locate military items being traded illegally. They soon discover, however, that there’s something far more serious at play – and they find themsel…