From June 1944, twelve Japanese seamen are stranded for seven years on an abandoned and forgotten island called Anatahan.

Three robbers escape with loot from a heist before one of them kills the others. Their corpses wash up near the aftermath of a maritime calamity, provoking a policeman’s interest.

While covering a test of guided torpedoes, two reporters believe they see what appears to be a strange-looking swimming creature. They investigate the matter further and discover that there is…