Jun travels by ship to investigate the mysterious disappearance of his old chum, Nomura, a member of a Japanese Antarctic Winter Party. Nomura's cryptic last message, "Peguila is here," beckoned Jun to Antarctica. Team Leader Amada and Jun eventually find the body of Nomura under a sheet of ice, guarded by his faithful dog, Saburo, who survived by eating native moss. The team discovers that the moss Saburo subsisted on is enriched with Peguimin H, a substance that is poisonous to Peguila. As the monster approaches their outpost, a rocket loaded with the Peguimin H is used to drive back the monster, though it flees to fight another day.
