The new season of Gotham premieres this Thursday night and have a wild and unpredictable season 3 finale, we can confirm that an original character is gone for good.
— Gotham (@Gotham) September 17, 2017
Gotham does tend to have characters die and then somehow coming back. This will not be the case for Fish Mooney. Fish Mooney was best known for her complicated relationship with Oswald Cobblepot aka The Penguin. She was thought to have died by the hands of Oswald during the season one finale.
We saw her resurrection by the hands of Doctor Hugo Strange as she was one of his patients at Indian Hill. She gained unique powers (which it seems like most of Gotham City has) and seemed to be close to regaining control of Gotham.
Fish's demise came at the hands of an infected Jim Gordon during an epic battle that left her former friend and now enemy Penguin stunned. She died in his arms as he told him if he can't rule Gotham, he should burn the city down.
Season 4 of Gotham premieres this Thurs., Sept. 21 only on FOX.