Perry Mason is intrigued when he sees Matilda Benson take a cigar out of her purse and light it. The case she wants him to handle seems simple enough: he's to go to a gambling ship moored just beyond the twelve-mile limit, and buy back the IOUs signed by Miss Benson's niece. But once Mason makes it out to the ship, he discovers a multitude of complications, most notably one of the ship's owners with a bullet hole through his head. And Matilda is on board that night—and so is her niece. Meanwhile, a couple on deck for some heavy petting see a gun tossed overboard...by a woman.