An avant-garde artist (Ann Prentiss) is sure that someone is trying to kill her and that her dead uncle's body isn't in its casket. Against Mac's advice, Pete takes on the assignment of helping Paula Wirehouse (guest star Ann Prentiss) try to establish whether her despised Uncle Barney is really dead and buried. After discovering Barney's casket empty, Pete and Paula beat a grave-robbing charge, only to witness several attempts on the lives of two people near and dear to them — themselves.

Joan Blondell portrays Delores Lear, the matriarch of a family that specializes in extortion. Joan Blondell guest stars as head of a family specializing in extortion, who tries to frame Mac and get him sent to jail to pay for her husband getting killed in prison. After being foiled once by Pete and Mac, Mrs. Lear returns to millionaire C.C. Owens and threatens to destroy his entire antique car collection unless he helps her frame Mac.