Disguised as "Miss Peggs" and elderly woman who has hurt her leg, she is escorted to wealthy Martha Travers yacht party by Martha Travers's nephew, Denny. She steals Martha's famous emerald necklace and hides it a bandage around her "injured" leg. Unfortunately she is caught when a fire warning is issued and she rushes to the lifeboats, proving her leg is not injured. Batman sees this and deduces her identity. She is captured but escapes before Batman can turn her over to the police.
Note: She is known as "The Cat" in this issue. Her real name is not given.