Book agent Margarita Solano inherits a dilapidated Spanish estate on a California coastal island, where the Native American housekeeper gives her a map to buried treasure. After attorney Maclyn Mills serves Margarita with a foreclose papers, he assists her and Captain Blunt in their search for the treasure. Their adversaries, Pedro, Spanish Joe, and the Rat, steal the map, find the treasure, and kidnap Maclyn and Captain Blunt. Margarita rescues them and retrieves the jewels from Pedro, after which they struggle at the edge of a cliff and fall into the shark-infested waters below. Pedro is eaten by sharks while Maclyn rescues Margarita.