When a man-sized bat ransacks Gotham harbor, Batman suspects that Dr. Kirk Langstrom is up to his old tricks, taking the Man-Bat formula again. Batman isn't the only one. Kirk's wife, Francine, is so distrustful of her husband that she decides to leave him. Though Kirk maintains that he's innocent, it takes a DNA test to prove to Batman that he's telling the truth. After further investigation, Batman discovers that Francine was accidentally infected by the Man-Bat formula and is probably the one transforming into the bat creature. By this time Francine is in a plane, flying out of Gotham. And she is starting to transform. It's a flight to the finish as Batman uses the Batwing to catch up to the plane and administer the antidote that will cure her She-Bat condition once and for all.