King Rat

George Segal is the mastermind of all black market operations in a Japanese prison camp. He is called "King Rat" because of his breeding of rodents to serve as food for his emaciated fellow prisoners. British officer James Fox helps Segal expand his operation to include trading with the Japanese officers. Though on surface level a thoroughly selfish sort, Segal saves the ailing Fox's life by wangling precious antibiotics from the guards. (official distributor synopsis)