Stalag 17 (1953) on Netflix

American Army Sgt. Clarence Cook, nicknamed Cookie, remembers back to late 1944, when he was a POW in Stalag 17, in barrack number 4 along with several other US army sergeants, and the one major problem at that time of what everyone in the barrack believed was a traitor among their ranks. Everyone in the barrack partook in most of the communal activities, such as trying to cause grief for their German captors - for example, in hatching escape plans - and trying to catch glimpses of the Russian female POWs at the adjoining camp, everyone that is except for Sgt. J.J. Sefton. Cynical Sefton, with Cookie as his paid help, only looked out for himself. He ran a gambling ring and sold homemade alcohol made from potato scraps among other schemes, and got rich on what passed for currency on the inside, namely goods within Red Cross packages, primarily cigarettes, which he would in turn trade with the Germans for other luxuries. Seemingly no means of "earning cigarettes" was too low for him. But several incidents occurred during this period which made it seem like the camp officials, namely the smug Commandant Oberst von Scherbach, and the barrack staff sergeant, J.S. Schultz, seemed to know their every move, especially those which may have involved escape plans - none of which were ever successful - or Allied efforts within the bigger picture of the war, leading to the thought that there must be a traitor inside. Sefton didn't really care about there being a traitor, until he was implicated as that traitor in a situation involving actions by US Army Lt. James Dunbar, who was housed temporarily at the stalag. Sefton then took it upon himself to find out the identity of the traitor,... or was he doing so just to take the focus of he truly being the traitor? Regardless, the follow-up issue was what to do with whoever the traitor when his identity was truly discovered if that ever did occur.