- "You're weak. You're all so damn weak. That's it. That is why Ra's chose me. Because he knew I would see how pitiful you all are. Afraid of change. Afraid to take orders from a woman. Well, listen up: I am the Demon's Head, so you sons-of-bitches better start bowing down right now, or it is gonna get ugly up in here!"
- —Barbara Kean to League of Shadows members
Arkham's "finest" give Gordon and Bullock a run for their money, as they hatch a plan to escape the asylum. Meanwhile, Bruce devises his own strategy to thwart their plans. Also, Barbara gets an offer she can't refuse.
Jervis Tetch breaks himself, Jerome Valeska, Jonathan Crane and eighty other inmates out of Arkham, before hypnotising hundreds of Gotham citizens to stand on rooftops to force Jim Gordon into an impossible situation. Though Tetch programs his victims to jump if they are told not to, Gordon finds a loophole and tricks the hypnotised people into saving each other, while apprehending Tetch. Bruce Wayne, blaming himself for not killing Jerome in their previous encounter, tracks him down with Selina Kyle's help, as Jerome tracks down his abusive uncle. Jerome's uncle tries to kill him but Bruce intervenes, and in the ensuing encounter, he chooses to spare Jerome again. Jerome kills his uncle after learning the location of someone he is searching for, and he and Scarecrow later rescue Tetch and head to 'St. Ignatius', pursued by Bruce, who alerts Gordon. Elsewhere Barbara Kean, forcing herself to remember the events surrounding her resurrection, learns that Ra's al Ghul revived her so she could replace him as the Demon's Head, and she assumes leadership of the League of Shadows with help from the organisation's female members, who kill their male comrades to protect her.
- Benedict Samuel (Jervis Tetch) makes his first appearence since "Heroes Rise: Heavydirtysoul".
- It is unknown when and how Jonathan Crane ended up in Arkham Asylum since he was able to escape the GCPD at the end of "A Dark Knight: The Fear Reaper".
- The designation number on Jerome Valeska's Arkham uniform is E-146. This is a reference to the comic Batman Vol 1 #46 (1948). The cover story of this comic, "Guileful Greetings, or, The Joker Sends Regards!", revolves around the Joker breaking out of jail, which parallels Jerome's plot in "A Dark Knight: One of My Three Soups".
- Barbara Kean’s resurrection after the events of "Heroes Rise: Heavydirtysoul" is shown in this episode.
- The Mad Hatter is the main antagonist of the episode and his routine of speaking in Rhymes passes to other characters throughout the episode.
- Robin Lord Taylor (Oswald Cobblepot) does not appear in this episode, the fifth in which he is absent. Also, Cory Michael Smith does not appear in the episode.
- Jerome Valeska and Selina Kyle meet each other.