Martha Travers, the wife of John Travers, is a wealthy older lady. She throws a party aboard her yacht "The Dolphin" to show off her famous emerald necklace. However the necklace is stolen by "The Cat" (Catwoman). Batman and Robin initially suspect her doctor, Dr. Wallace and her brother, Roger. However it turns out it's actually her nephew, Denny, who was working with the Cat. Batman eventually recovers her necklace.