The serial is set on a remote island near the Mexican border, where the island's ruthless owner Carter Collins holds half of an antique treasure map leading to a cache of gold hidden somewhere on the island. Reporter Larry Kent arrives on the island in search of another reporter who had gone missing. Local postmaster Toni Morrell is summoned by Captain Tom Faxton who, on his deathbed, gives Toni the other half of the treasure map, left to her by her father—but Faxton expires before he can divulge the identity of Toni's father. Larry and Toni, besides being opposed by Collins, are threatened by a hoodlum named Gridley, who disguises in a skull mask and pirate clothing. When the disguise fails, Gridley resorts to desperate means to grab Toni's map.