Sergeant David Callahan leads a task force of U.S. Marines sent in behind enemy lines to perform a secret mission. The mission becomes a failure, when commandos kill the daughter of powerful Captain Vinai. Five years later Callahan lives in Thailand, and works as a secret adviser of the Thai Special Forces. Unfinished feuds from Callahan's past return, and the soldier is forced to come back to the Vietnamese P.O.W. camp he escaped years before, then fight off a deadly duel.