’Dexter’ Trinity Killer Prequel: What To Know About The Spin Off (2025)

Good news, Dexter aficionados: the franchise is officially out of control.

Eight seasons of the original series were survived by Dexter: New Blood, which was supposedly the end, but Dexter Morgan somehow survived again to cameo his way into Dexter: Original Sin, which introduced the younger serial killer during the formation of his Code. That wasn’t enough.

Dexter: Resurrection is currently filming with Michael C. Hall and a bevy of original cast members, including James Remar (as Harry), David Zayas (as Angel Batista), and John Lithgow (as Arthur Mitchell, the Trinity Killer). What? Yes, Arthur will not only be back in that sequel, but he is going to receive his own prequel spin off. Let’s look at the evidence on what to expect.

Plot

Specific plot details are under wraps, and we can guess that the vibe will be similar to Original Sin but focused primarily on the Trinity Killer’s earlier crimes. As his nickname suggests, he killed in threes and amassed hundreds of victims throughout the U.S., so there should be no shortage of material for at least a season. The prequel will also presumably bounce off whatever transpires with Arthur Mitchell’s appearance in Dexter: Resurrection. Notably, Lithgow has revealed the Trinity Killer, a fourth-season antagonist whose arc reverberated beyond his physical appearance, did not die despite Dexter apparently bludgeoning the life out of him with a hammer.

Sure, that doesn’t seem possible, but Lithgow informed Variety, “I just went back to do a day,” and “it turns out he didn’t die after all. I come back sort of as a phantom, as he gradually comes to life on a hospital bed.” Oh, just roll with it. That will also happen in a cast that includes Krysten Ritter, David Dastmalchian, Peter Dinklage, and Uma Thurman, in addition to Michael C. Hall and the returning cast members mentioned above.

Maybe in Resurrection, Dexter can get the job done this time on killing Arthur Mitchell, and then, it’s back to his origin story with the next prequel series, which is already scripted. Last December, universe architect Clyde Phillips revealed (as reported by Deadline) that Lithgow will lend his voice:

“We wrote the entire Trinity Killer series. At the moment, it is on the back burner. John Lithgow has agreed to be the voice of his younger self the way Michael Hall is doing for [Original Sin]. There’s that and we’re doing another show with Michael C. Hall, [Resurrection]… We were writing that while shooting Original Sin, so that’s fairly busy. We begin shooting [Resurrection] in January and it will air in June 2025.”

Lithgow, however, dodged the question on whether he’ll narrate while speaking with Screenrant. He did offer a suggestion to the mystery actor filling Trinity’s younger shoes: “Just be on his side. [Laughs] Not an easy thing to do, with the Trinity Killer, but be on his side.”

Cast

Showtime hasn’t yet revealed who will portray the younger Arthur Mitchell, and surely, Lithgow will monologue, although no word has surfaced on whether he will cameo like Michael C. Hall did for Original Sin.

Release Date

Dexter: Resurrection will be out this summer, and Trinity should not be too far behind once filming begins since Original Sin came together pretty darn fast. 2026? Maybe.

Trailer

No trailer exists yet, but hey, here’s a clip of Dexter apparently not doing a good enough job of killing Arthur Mitchell.