Here is the official description for the season finale of Gotham, "All Happy Families Are Alike". Episode 22 airs on May 4th.

Season 1 Episode 22 "All Happy Families Are Alike"

THE BATTLE BETWEEN GOOD AND EVIL RAGES ON THE ALL-NEW SEASON FINALE

As Gotham City’s gang war reaches its boiling point, Fish Mooney goes head-to-head with Maroni and Penguin in an attempt to re-stake her claim on the city. Meanwhile, Barbara and Leslie Thompkins are brought together after recent events, and Bruce searches Wayne Manor for any clues that his father might have left behind.