When Singapore surrendered to the Japanese in 1942, the Allied P.O.W.s, mostly British, but including a few Americans, were incarcerated in Changi prison. This was a P.O.W. camp like no other. There were no walls or barbed-wire fences, for the simple reason that there was no place for the prisoners to which to escape. Included among the prisoners is the American Corporal King (George Segal), a wheeler-dealer who has managed to established a pretty good life for himself in the camp. While most of the prisoners are near starvation and have uniforms that are in tatters, King eats well and and has crisp clean clothes to wear every day. His nemesis is Lieutenant Robin Grey (Sir Tom Courtenay), the camp Provost who attempts to keep good order and discipline. He knows that King is breaking camp rules by bartering with the Japanese, but can't quite get the evidence he needs to stop him. King soon forms a friendship with Lieutenant Peter Marlowe (James Fox), an upper class British officer who is fascinated with King's style and no-rules approach to life. As the story develops, it reveals the hypocrisy of the British class system and for King, the fact that his position in Changi's "society" is tenuous as best.