Professional contract killer Duke Togo—codenamed "Golgo 13"—is hired to assassinate Robert Dawson, the son of oil baron Leonard Dawson and the heir of Dawson Enterprises, and succeeds. Later, after accomplishing a hit on a powerful crime boss in Sicily, Golgo is suddenly attacked by the U.S. military and discovers that his informant, the clockmaker, has been killed by Snake, a genetically altered assassin. Aided by The Pentagon, the Federal Bureau of Investigation, and the Central Intelligence Agency, Dawson has become determined to kill Golgo and avenge his son's death.