Gotham's fourth season has been going all out to show the city at its craziest.

With a strong focus on Jerome Valeska and his twin brother Jeremiah, the series' latest move was to go full Joker and explore the rise of Batman's most devious and maniacal villain. And now that the Joker is present all but in name, is it possible that Gotham might be teasing an actual appearance of his longtime partner-in-crime/girlfriend, Harley Quinn?

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The series' latest teaser offers a glimpse at things to come, and it appears that although Jerome is now dead, his presence will continue to be felt throughout Gotham City. Worse still, it looks like he might inspire a whole new crop of clown-inspired villains to terrorize the citizens. Most notably, the trailer gave us a glimpse at a woman wearing a court jester-like mask and costume. She may not be clad in clear red and black, but the faded look instantly screams Harley Quinn. This is but another tease in a long line of Harley Quinn nods, despite Gotham never allowing the full character to debut on the Batman series.

This is far from the first time Gotham has toyed around with the prospect of Harleen Quinzel making a grand entrance, of course. There was a time when viewers believed Barbara Kean would turn into the series' version of Harley, especially after she was used as a stage-assistant of sorts to Jerome's proto-Joker.

It was later confirmed that while Barbara would not be Harley, the character would debut in the Season 3 finale. But then, the finale came and went, and Harley was nowhere to be seen, prompting even more theories about which already-established character might turn into the Joker's future girlfriend.

But then, the Gotham producers said that Harley Quinn would never be a part of the show. Obviously, fans of the character were left disappointed by the comment. After so many teases and nods, it almost seemed an cheat to remove Harley from the board.

It appears Gotham's producers aren't done playing with the emotions of Harley Quinn fans just yet. A female harlequin mask-wearing villain is set to appear in the series' upcoming episodes, in the clearest nod to the character yet. But is Harley Quinn truly making her debut now, is this simply another tease, or are we looking at the introduction of a proto-version of Harley, in the same way that Jerome was the first proto-Joker? Or perhaps it's going to be a major swerve and be revealed to be a gender-swapped version of Punch, the partner of DC Comics' B-level villain Jewelee?

Since Jeremiah is all but set to become the series' version of the Joker (the trailer seems to make that transformation explicit), it would seem logical for Gotham to follow up by introducing Harley Quinn as his partner in crime. That way, the duo could now launch their very own brand of maniacal terror on the city. The woman underneath that costume might very well be someone we've already seen on the show, with ties to Jeremiah. Ecco was introduced on the series very recently, as Jeremiah's assistant and personal guard. She packed a mean punch (and kick) and, were she to put on a jester costume, would make a fine addition to Gotham's rogues gallery.

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Airing Thursdays at 8 p.m. ET/PT on Fox, Gotham stars Ben McKenzie as James Gordon, Donal Logue as Harvey Bullock, David Mazouz as Bruce Wayne, Robin Lord Taylor as Penguin, Camren Bicondova as Selina Kyle, Erin Richards as Barbara Kean and Sean Pertwee as Alfred Pennyworth.