Earlier this year, Gotham announced that Alexander Siddig (Game of ThronesDeep Space Nine) would be joining the show's cast as Ra's Al Ghul. Now, in a promo for the show's two-hour Season 3 finale, it appears the head of the demon has finally arrived in Bruce Wayne and Jim Gordon's city.

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The finale's official description states:

With the deadly virus spreading throughout the city, the search for the antidote continues, as Fish Mooney (guest star Jada Pinkett Smith), The Riddler and Penguin reveal plans of their own. Bruce meets Ra’s Al Ghul (guest star Alexander Siddig) and completes his last task in order to fulfill his destiny, but realizes he can’t let go of his past. Meanwhile, Gordon tries to win back Lee, and past alliances within Gotham City are broken, while new alliances are formed in the all-new, special two-hour “Heroes Rise: Destiny Calling/ Heroes Rise: Heavydirtysoul” season finale episode of GOTHAM.

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Starring Ben McKenzie as Detective Jim Gordon, Gotham's third season concludes Monday, June 5 at 8:00-10:00 PM ET/PT on FOX. The series also stars David Mazouz as young Bruce Wayne, Camren Bicondova as young Selina Kyle, Donal Logue as Harvey Bullock, Robin Lord Taylor as Oswald Cobblepot, and Morena Baccarin as Leslie Thompkins.