In the Batman Beyond comic series set decades after Batman: The Animated Series, it is revealed that shortly after Batman cured Francine of the Man-Bat serum, she and Kirk started to live a peaceful life as they started studying sonics and had two children. However, Francine developed an aggressive form of Parkinson's and had a short life expectancy, leading Kirk to try and perfect the Man-Bat serum to save her life. But by the time he made it, it was too late. Following this, his children left him, angered that he did not spend as much time with her during her final days. Devastated by "losing" his family, Kirk turned to the serum, which has been perfected to the point where he is able to talk and control his actions, and had been living in secret as Man-Bat ever since. Three years prior, he rescues a girl named Tey, who was a hostage of the Jokerz, and injects her with the Man-Bat serum, leading the two to fall in love. In the present, Kirk, now as a white-bearded Man-Bat, tries building his own cult of Man-Bats, plans to use Kanium to help his cult control themselves better in their Man-Bat forms and sets up a destructive weapon that concerns the police. Bruce tries to reason with Kirk, but it only results in Kirk viewing the both of them as monsters and setting up his bomb to destroy the two of them. However, Batman rescues Bruce in time as Man-Bat tells Bruce to use his second chance wisely as he detonates the bomb to kill himself.