A Japanese woman is killed while making a report to her British contact. Under the guise of a reporter, secret agent John Drake visits Tokyo to investigate. He suspects that an ancient death cult is making a resurgence and begins asking around about a pendant found at the murder scene. His search brings him to a theater, where he meets an Englishman, Sanders, watching a group of actors rehearsing the Koroshi - the death scene. Drake believes he has found the lead he is looking for, but Sanders also begins to suspect Drake and attempts to do away with him.
—Twenty Penguins