First the good bits and that mainly centres around Simone Signoret, who as usual is excellent. But this poses a problem, for the "love-affair" of the film, which involves her and a young Gordon Jackson who looks and acts as though he had never been out of Cowdenbeath. So hardly the material to interest a sophisticated European lady as played by Ms. Signoret. Not good casting, indeed one of the more ridiculous romantic combinations in the history of motion pictures.
That being said the film, in black and white, has some atmosphere, tension and you feel that you are there, which is important. The rather bizarre casting continues, however, with the unlikely scenario of a rather elderly Jack Warner playing the part of a commando. Still if he was still an active policeman at 80 years of age in Dixon of Dock Green , who are we to argue with his credentials. In addition he is part of the two most memorable scenes in the film, one when he meets the Irish girl working for the Germans and secondly when he has to contend with a very angry Ms. Signoret holding a pistol.
James Robertson Justice is, as always, very believable as the organiser of the missions working from base and there are some good supporting actors who play around his character. For some reason the part played by John Slater irritated me from start to finish, though the rest of the cast, including Robert Beatty, were sound if a touch wooden.
I would summarise this film as a pleasant and nostalgic way to spend a rainy afternoon and if it is on sale for around £5 then worth a look.