The movie feels less like a standard action story and more like a collection of situations designed to communicate the idea that unguarded words can have serious consequences. Its origins as a training exercise are evident in the somewhat awkward editing style, suggesting director Thorold Dickinson adapted his approach as this project for the military evolved into a significant weapon against enemy intelligence operations. A strong ensemble cast featuring active and reserve soldiers like Mervyn Johns, Jack Hawkins, Stephen Murray, Basil Sydney, and Torin Thatcher—playing the villain as usual—helps to tell a story that demonstrates how easily information could fall into the wrong hands and be exploited. The film incorporates actual footage at times, creating an unusual kind of suspense, particularly because the outcomes of each storyline aren't always positive for the British side, which contributes to its sense of realism. There are moments of dark humor from the wartime era as well, and while it’s a peculiar film to experience, I found its distinct believability engaging and, in many ways, quite pleasurable.

Source on TMDB