When the head of the Gotham City Police Department is attacked, Det. Harvey Bullock must take over as Chief, leading the investigation into the reappearance of Dr. Victor Fries, a.k.a. "Mr. Freeze." What does the return of a believed-dead scientist have to do with the new head of Arkham Asylum, Hugo Strange? Meanwhile, with her boyfriend in jail for murder, Dr. Leslie Thompkins chooses to leave Gotham City forever.