Once every year on April Fool's Day, an unidentified villain robs one of Gotham City's banks of exactly $100,000. That thief is none other than Zelda The Great, a world-famous magician/escape artist who uses the ill-gotten gains to pay off a strange Albanian mastermind answering to the moniker of Eivol Ekdal. Batman decides to trap the thief by planting a story in the newspaper claiming the stolen money was counterfeit. When Eivol reads the fake article, he refuses to give Zelda his latest device, The Inescapable Death-Trap, until his demands are met.
Noticing a story about a rare gem on display in a local jewelry store, Eivol sends Zelda to swipe the gem in exchange for his creation. Zelda finds that the gem is a trick and confounds our heroes when she successfully steals the jewel and throws it away. She calls to Aunt Harriet and dupes her into believing her nephew Dick Grayson has been injured by a pop fly ball and lures her to the Gotham playground. There Zelda kidnaps Harriet and spirits her away to her hide out encasing her in a straitjacket suspended over a vat of boiling oil and holds her for ransom!!