To get money for her seriously ill boyfriend's treatment, sexy Sally Madison is extorting wealthy Harrington Faulkner. Faulkner is only too willing to pay--in exchange for a wonder cure for his ailing tropical fish. When the fish get filched, Faulkner wants the thieves to pay--but instead, he does with his life. Enter Perry Mason, who's casting his line for suspects, and wondering if he's swimming with sharks.