WARNING: The following article contains spoilers for the latest episode of Gotham, "Ruin," which aired Thursday on Fox.

Last night's episode of Gotham ended with a major shocker: Selina Kyle walked up to Jeremiah Valeska, who shot and paralyzed her in Season 4, and repeatedly stabbed him in the chest. Following the attack, the would-be Joker was left for dead, with no hints of a potential resurrection.

But given the character's prominence on the series, and that previous trailers for the final season have shown Valeska in action at ACE Chemicals, it seems unlikely the character did, in fact, die in "Ruin." However, the preview for Gotham's next episode, "Pena Dura," seems to confirm that Jeremiah is really and truly dead.

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The promo begins with Barbara Kean celebrating Selina Kyle as Jeremiah's killer, as we see Jeremiah's body laying on what appears to be a slab. What's more, the look of disapproval on Bruce Wayne's face as he watches Selina echoes the signature rule of the future Caped Crusader: no killing. It's just one more piece of evidence that seems to indicate that Jeremiah Valeska is really dead.

Cameron Monaghan's maniacal killer arrived late in Season 4 of Gotham as the twin brother of the now-deceased Jerome Valeska. The story of these two brothers has been intertwined with the rise of the Joker on the series, an origin that has been as twisted as unpredictable. Recently, Monaghan stated that he would play a third mysterious character on the series -- a character who will, more than likely, turn out to be the real Joker.

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Either Gotham has managed to deal a real surprise with the abrupt death of Jeremiah or, like his brother before him, he will be resuscitated. The simple fact that we see him on a slab in the preview would indicate that this story is far from over.

On top of confirming this major death, the promo for "Pena Dura" also shows the much-discussed debut of Shane West as Eduardo Dorrance, who is bound to become the series' version of Batman villain Bane.

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.