Jason Isaacs played Captain Gabriel Lorca in the first season of Star Trek: Discovery. Dark, cold and mysterious, Lorca often made decisions challenging the ideas of what a proper Starfleet captain should be. He justified every action he took, regardless of how controversial or extreme that action was, but it always seemed like he was harboring some dark secrets. Well, at the end of the show's first season, the captain of the Discovery is revealed as a fugitive from Star Trek's Mirror Universe that assumed the identity of his Prime Universe counterpart. But while that explains why Lorca was so determined in his mission, the fate of his Prime Universe counterpart was still a mystery.
In the episode "Vaulting Ambitions," Michael Burnham discovers Lorca's true identity as a member of the Mirror Universe and the Terran Empire. It's revealed that Lorca escaped to the Prime Universe after staging a coup against Emperor Philippa Georgiou and is believed to have murdered her adopted daughter, Burnham's Mirror Universe counterpart. Upon his arrival in the Prime Universe, Lorca assumed the identity of his counterpart and eventually became captain of the Discovery. Fortunately, Lorca ultimately fails in his objectives, and Emperor Georgiou kills him after a brief struggle by stabbing him with a sword and pushing him into her ship's reactor core.
Lorca's demise so early in Discovery's run came as a surprise, but there is a chance Jason Isaacs could return to the franchise in the future, given the status of his Prime Universe counterpart. While Discovery hasn't revealed what happened to Prime Lorca, Drastic Measures, a tie-novel written by Dayton Ward, reveals he's still alive and imprisoned in the Mirror Universe. The novel takes place ten years before "The Battle of the Binary Stars" episode and follows Prime Lorca, then a Lt. Commander, as he and Commander Georgiou confront a devastating contagion affecting the Federation colony Tarsus IV.
In an interview with EW, Isaacs revealed details about Prime Lorca and how he ended up in the Mirror Universe. "There was a Prime Lorca, he was captain of the Buran in the Prime world," he explained. "He swapped with him and found himself captain of the Buran. This never came out, this backstory detail we never put in the dialogue: Lorca spins this story having had to sacrifice the men on Buran and had to blow them up to save them from Klingon torture. Actually, if I remember correctly, there was some kind of DNA identification that would have exposed Lorca as not being Prime Lorca, and so he blew up the ship and killed everyone on it."
So, as far as canon is concerned, Prime Locra still finds himself stuck in the Mirror Universe. But the character could still have a future in the franchise, as Yeoh is set to return as Georgiou in her own spinoff titled Section 31. Though details on the show remain few and far between, Lorca is closely tied to the former Emperor of the Terran Empire, leaving the door open for him to return.
Streaming on Paramount+, Star Trek: Discovery stars Sonequa Martin-Green as Commander Michael Burnham, Doug Jones as Commander Saru, Anthony Rapp as Lt. Commander Paul Stamets, Mary Wiseman as Ensign Sylvia Tilly, Wilson Cruz as Dr. Hugh Culber, David Ajala as Cleveland "Book" Booker, Blu del Barrio as Adira, Ian Alexander as Gray, Tig Notaro as Chief Engineer Reno and Michelle Yeoh as Philippa Georgiou. Seasons 1-3 are currently available to stream on Paramount+, with Season 4 premiering later this year.