For doing such a great job, Lois and Clark are given a cruise vacation aboard the "Grenodier", where they meet Nan Wilson, who has inherited Pogo Island, and she invites the two to visit her island. But the superstitious natives believe that Nan is a witch and several attempts are made on her life. Superman, however, discovers that the island is being used as a base for submarines belonging to a foreign nation which prey on merchant marine vessels in neutral waters.; After investigating three mysterious deaths, Clark Kent writes an article on the deaths, which he believes are actually murders, carried out by the same man, a man of unusual criminal intelligence. When Superman investigates, he discovers the case is much more complex than he first thought, but proves his theory to be correct.; After a series of explosions at American defense industries, Superman rounds up members of the Grotak Bund, an organization that has orders to destroy certain American factories to seriously slow down U.S. defense operations.; Lois and Clark excitedly listen to a story by a scientist, who tells them of a forced visit he made to Baracoda Island, where giant animals were artifically being breeded. However, when he discovered that he had become part of a plot to use the animals to conquer the world and set up a scientific dictatorship, he wanted no part of it and escaped to warn the outside world.