Brisk, no-nonsense British war movie (from Rank), tersely directed by McCarthy (whose background was in documentary) and full of unfussy, businesslike performances. Tony Britton leads a mission to Amsterdam in the summer of 1940 (the eve of the Nazi invasion) to prevent a valuable stash of industrial diamonds falling into enemy hands. Time is short - the Germans are only hours from town - but Britton and his crew make sure they get the job done. The one real casualty here is characterisation - there's such an onus on keeping the narrative moving that we get precious little chance to learn what makes the heroes tick. Adapted by the director and John Eldridge from the book Adventure in Diamonds by David E Walker.