Ra’s al Ghul will play a big role in the upcoming season 3 finale of Gotham, but he won't be the only Batman villain in Season 3's final episodes. According to MoviePilot, series star David Mazouz -- who plays young Bruce Wayne -- has confirmed that Harley Quinn will also make her debut on the show this season.

Asked about Harley Quinn at the Heroes & Villains Fan Fest in London, Mazouz said, "She's going to be in the finale. Stay tuned."

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The actor also hinted that his character will make a fateful choice that may well set the tone for show's fourth season by the seasons' end. "Something major happens in the very last scene of Season 3 for Bruce," Mazouz teased. "He makes a decision, that decision will influence what he does. I don't know what's happening in Season 4 yet, I haven't had a script or talked to the writers about what's going to happen, but where I see it going is somewhere I've wanted to see it going for a very long time. You'll see what I mean. Bruce is going to be very busy taking on this new role that he assumes at the end of Season 3 and I think it'll be really cool."

Starring Ben McKenzie as Detective Jim Gordon, Gotham's third season concludes Monday, June 5 with the final two episodes premiering back-to-back starting at 8 pm 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.