The midseason finale of "Gotham" season 4 was much-buzzed-about, especially with a familiar face resurfacing at the end of the episode. A new extended trailer for the upcoming episode has another reference to Batman's greatest enemy.

The preview for episode 12 of season 4 starts off with Jerome Valeska (Cameron Monaghan), who is pretty much the Joker at this point. He has scars on his face, dark circles under his eyes and sports a much shorter hairstyle. The scene then cuts to a Joker card being placed on the floor.

Fans of the show know that this is not the first time that a shot of the Joker card has been featured in the series. The first occurrence was in the third season, where the first of three episodes centered on Jerome. Could it be the show hinting, or possibly confirming, that Jerome is the Joker? Perhaps, despite executive producers saying otherwise.

When "Gotham" season 4 returns from its winter break, Jerome will be teaming up with none other than Oswald Cobblepot/Penguin (Robin Lord Taylor), who was dethroned as the king of Gotham's criminal underbelly.

The upcoming episode's trailer shows the two of them together, with Jerome perhaps challenging Penguin to make him laugh. Penguin initially shuts that idea down, but a later scene shows him beating Jerome, and that is enough to make the supposed Joker laugh.

By the end of the trailer, Jerome tells Penguin that they will have so much fun as they start to cackle behind their cells at Arkham Asylum.

Of course, the preview is not just about Jerome. It also teased other storylines and events that will take place in the second half of season 4. The next of which is Captain Jim Gordon (Ben McKenzie) and his goal of trying to restore peace, yet again, to the maddening city.

He is seen talking to Sofia Falcone (Crystal Reed) and says that if he is going down, then she will go down with him too. Sofia then counters by saying, "You still think you know what I will and won't do."

Sophia will obviously continue to twist Gordon's arm as she takes over the city as the sole Falcone.

And, of course, there is also Bruce Wayne (David Mazouz). Bruce has been quite the angsty billionaire party boy as of late, and the preview shows him possibly snapping out of that phase and returning to his vigilante ways.

Bruce put an abrupt halt to his vigilante ways after he supposedly killed Ra's al Ghul (Alexander Siddig), thus breaking his "no killing" rule.

The preview also shows the first look at the new version of Ivy Pepper/Poison Ivy, now played by Peyton List. Ivy was last seen downing so many bottles of magic potions after having had enough of being disrespected by Penguin and just about everyone.

Poison Ivy is seen coming out of what look like shrubs. Perhaps this is where she suddenly develops her powers. Later on, she is seen talking to Bruce in Wayne Manor, and he only recognizes her when she calls him "Billionaire Boy."

Meanwhile, Mazouz spoke to ComicBook about what to expect in the remaining episodes of the fourth season, as well as what Jerome's return means for his character.

As fans can recall, Bruce and Jerome have had about two confrontations over the course of the show. It seems that his resurfacing will prompt Bruce to suit up again. Although, this time, he would be on his own, without the guidance of Alfred Pennyworth (Sean Pertwee).

Mazouz revealed that the second half of season 4 will have "one of the worst episodes in 'Gotham' yet," with things inevitably getting worse. The actor added that not only will there be a Jerome-Penguin team-up, but the former will also be partnering up with other rogues who are also anything but likable.

Compared to the last time, battling the rogues of the city will no longer solely rest on Gordon and the GCPD. As previously mentioned, Bruce will join the fold in order to come after Jerome, further hinting of what his future self will be doing in the future.

"Gotham" season 4 will return to FOX in spring 2018.