During World War II, an American marine pilot (LEE MARVIN) is shot down and finds his way to a small, unpopulated island in the Pacific where he hopes to find provisions. He soon discovers that he is not alone when he is stalked by a Japanese navy officer (TOSHIRO MIFUNE) who is also marooned on the tiny tropical island. The Japanese officer captures the American, but this situation is reversed when he manages to escape. Their conflict is sometimes more than just mere survival, but rather an extension of the war being waged in the Pacific Ocean. Will they come to rely on each other to survive, or will they fight each other to the death?