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.

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.

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.

The effects of a recent incident begin to cause Barnes to go mad; Nygma is over his head in his relationship with Isabella; Carmine Falcone throws an engagement party for Lee and Mario.

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.

Temple Shaman takes Bruce to the next phase of his training; Gordon and Bullock discover a crystal owl that carries the biggest secrets of Gotham's underworld; Nygma and Penguin must work together to get out of a tricky situation.