Lorelei Circe, aka The Siren, launches a two part plan to become the richest and wickedest woman in Gotham City. First she puts Commissioner Gordon under her stunning spell and orders him to stow away in the Batmobile in order to find out the location of the Batcave as well as Batman & Robins secret identities. Secondly she entrances millionaire playboy Bruce Wayne and implores him to sign over all his wealth and belongings to her.

The Penguin teams up with parasol collector Lola Lasagne. Together, they plan to rig the upcoming Bruce Wayne Handicap to make a fortune from Lola's prize racehorse Parasol. They break into Glu Gluten's Glue Factory to steal a condemned horse, planning to switch horses before the race and make their money by betting on the real Parasol. When Batman, Robin, and Batgirl catch up with them at the glue factory, Penguin sneaks outside and plasters the Batmobile with a sticky glue.

The Penguin steals a priceless folio of famous parasols from the Gotham City Library. He plans to wager the $10,000 earned from its ransom on a rigged horse race. Aided by his partner-in-crime Lola Lasagne, he disguises the favored entry Parasol as the unknown "Bumbershoot," then enters a painted glue factory horse as "Parasol". With everyone betting their money on the fake horse, it looks like the Penguin will make a fortune when the real Parasol wins the race. But he wasn't counting on a last-minute entry of Bruce Wayne's, the horse Waynebow, ridden by none other than Batgirl.