In the GCPD, Bullock (Donal Logue) announces to the media Azrael's death caused by "unknown perpetrator(s)".

In Arkham Asylum, Professor Strange (B. D. Wong) along with Peabody (Tonya Pinkins), are now performing a test on a patient, Basil Karlo (Brian McManamon), who can now stretch his skin.

Gordon talks with Lucius (Chris Chalk) about infiltrating Arkham Asylum to find the secret lab and they, along with Bruce, decide to go.

Selina is forced to harm her with the flamethrower but to her shock, Bridgit is now immune to the fire as her fire-proof suit was fused to her.

In April 2016, it was announced that the twenty-first episode of the season would be titled "A Legion of Horribles", and was to be written by Jordan Harper, with Rob Bailey directing.

[4] Morena Baccarin, Robin Lord Taylor, Erin Richards, James Frain, Jessica Lucas, Drew Powell, Nicholas D'Agosto, and Michael Chiklis don't appear in the episode as their respective characters.

In April 2016, it was announced that the guest cast for the episode would include Jada Pinkett Smith as Fish Mooney, B. D. Wong as Professor Hugo Strange, Tonya Pinkins as Ethel Peabody, Clare Foley as Ivy Pepper, Michelle Veintimilla as Bridgit Pike, Kit Flanagan as the White-Haired Woman, and Brian McManamon as Basil Karlo.

[6] With this rating, Gotham ranked first for FOX, beating Houdini & Doyle, fourth on its timeslot and ninth for the night on the 18-49 demographics, behind Blindspot, The Odd Couple, Castle, a rerun of The Big Bang Theory, two episodes of Mike & Molly, Dancing with the Stars and The Voice.

[10] Matt Fowler of IGN gave the episode a "good" 7.6 out of 10 and wrote in his verdict, "'A Legion of Horribles' messily worked its butt off to get everyone into one spot.

And while Clayface and the Court's debuts were fun, Fish Mooney's return felt like a curious decision given how crowded the show is now and the mixed reactions she received back in Season 1.

Club's Kyle Fowle gave the episode a "C−" grade and wrote, "Gotham consistently tosses emotional investment to the side.

When the most memorable and impactful moment is the return of a character everybody knew was coming back because of heavy promotion, there's a serious problem.

"[12] Andy Behbakht of TV Overmind gave the series a star rating of 4 out of 5, writing "Overall, 'A Legion of Horribles' lived up to its title as it sets up what I bet will be a crazy season finale next week.

I'm not a comic book buff by any means, but the Court of Owls is an organized crime group and secret society that's been in Gotham for a very, very long time.

"[13] Karmen Fox of The Baltimore Sun wrote positively about the episode, "Bruce's mission to find his parents' killer just got a little more complicated.

The visible and narrative tone has taken a turn for the serious, and Season 2 Gotham has forged forward with Baby Batman and Hilariously Unlikeable Jim Gordon with confidence.

What once were weaknesses — Baby Batman was too Batman-y too fast; Jim Gordon was unbearably unlikable in a totally unfunny way — have been turned into strengths of their own.

Bruce's story has turned genuinely interesting, with his relationship with Selina forming the foundation for all the hard decisions we know he will have to make as Batman later on in his life.