Gordon works in a monster-ridden Gotham as a bounty hunter and seeks to find answers about the Indian Hill escapees, and why their powers appear to be killing them. Meanwhile, Bruce’s doppelganger roams the streets, and Barbara and Tabitha open a new nightclub called The Sirens.
Fish Mooney takes matters into her own hands to locate Hugo Strange, forcing Gordon to reluctantly team up with journalist Valerie Vale to find her. Penguin rises in popularity after criticizing the work of the GCPD and Bruce's investigation of the Court of Owls is compromised. Meanwhile, Ivy Pepper is reintroduced into Gotham city.
Hypnotist Jervis Tetch/Mad Hatter arrives in Gotham to search for his sister, Alice, and hires Gordon to help find her. Meanwhile, Penguin decides to run for mayor and Bruce's doppelganger begins to channel him, causing some confusion around town.
Crime in Gotham is at an all-time high, as Penguin struggles to uphold his promises to the city. Meanwhile, Butch goes down a dark path with the infamous Red Hood Gang and Bruce begins to investigate Ivy's whereabouts.
Mad Hatter sets his eyes on his next victims, forcing Jim Gordon to make some tough decisions. Meanwhile, Penguin and Nygma's relationship evolves, and a familiar face comes back into Nygma's life.
After coming in contact with a substance by the hand of Mad Hatter, Jim Gordon gets led on a psychedelic trip and must confront his past, present and future. Meanwhile, Penguin struggles with Nygma's new relationship.
Barnes begins to feel the effects of a recent incident and begins to go mad. Meanwhile, Nygma is out of his depth in his relationship with Isabella and Carmine Falcone throws Lee and Mario an engagement party.
Gordon and Bullock become suspicious of Barnes, and comb through evidence of the murder at Lee and Mario’s engagement party. Nygma goes to Penguin when he hasn’t heard from Isabella. Meanwhile, Ivy reveals her identity to Selina and Bruce, but quickly leads them to trouble.
On the eve of their rehearsal dinner, a threat to Mario and Lee is exposed, and Falcone looks to Jim for help. Meanwhile, Nygma seeks revenge and Bruce learns more about The Court of Owls.
As the virus begins to spread in Gotham, the laboratory that is developing a cure is compromised. Mario and Gordon face off before the wedding, Selina meets an unexpected face and Barbara comes to Nygma with information about Isabella.