Lewis Gilbert was a very reliable director, not one of the top ones and not one of the most active, but the films he made are always well made, like for instance maybe the best James Bond, "You Only Live Twice". This is another of his very best, although in black and white and behind barbed fences in a dreary muddy war prison camp. The story is a true one, and it is marvellously developed, gradually mounting in suspense and intrigue, as one of the Germans gets acceleratedly vicious in his frustration, taunted by his insolent but honest prisoners. His villainy is actually more outrageous than usual for bullying Germans in the war, which must lead to some sort of settlement. No one will be disappointed.
There are many films like this, true stories of incidents and escape ordeals in war prison camps towards the end of the war, and this is clearly one of the best, almost on par with "The Password is Courage" (1962) with Dirk Bogarde, an equally true and fantastic war prison story of epic esacapes.