Billy investigates the mysterious disappearance of the freighter, Red Star, last seen near the coast of Greenland. There he discovers that Rodney Stark has invented a machine that slowly melts ice, freeing prehistoric men, whom he uses as slaves to build a massive airforce to attack and subdue the United States.; Carol's murderous uncles hope to convince her that her gold mine is haunted. Golden Arrow exposes their plot to acquire the mine for themselves.; Lance and Cap'n Doom help Gail recover a treasure in gold from her father's sunken ship.; Hal's father bequeaths his practice among the Blancas, a white tribe in Brazil, to Hal. A jealous medicine man stirs up fear of Hal and it's only after a knife duel that Hal can reassert himself as a friend of the Blancas.