Riddle U.After learning that the Riddler has power and clean water, Harley, Ivy, and Clayface make plans to infiltrate his stronghold, "Riddler University", while King Shark and Doctor Psycho venture through Two-Face and Bane's territories to secure a water filter. Harley nearly blows her cover in front of the tour guide, Barbara Gordon after she attacks the mascot thinking that he was The Riddler. Harley and Ivy track down Barbara to kill her before she can warn the Riddler, but she tells them she wants to stop him after deducing he was responsible for kidnapping students ever since he took over and that she procured invitations for a party at a fraternity house where the disappearances occurred...