Star Trek: Discovery said goodbye to a fan-favorite cast member in today's new episode, "Terra Firma, Part 2." SPOILERS for the episode follow. The two-part "Terra Firma" story is about figuring out how to help Philippa Georgiou, whose body is breaking down after Discovery's jump to the 32nd century. Thanks to some helpful exposition from David Cronenberg as Kovich, we know this results from her jumping through both time and dimensions. A jump in either time or space is one thing, but doing both is more than a person's atoms can handle, and the former Terran Emperor is no exception.
Luckily for her, the sphere data still living in Discovery's computer finds an answer. Michael Burnham takes Georgiou to what seems like a frozen planet devoid of life. They're surprised when a man named Carl wearing anachronistic 20th-century Earth clothes shows up. He offers Georgiou the chance to walk through a door. She finds herself back in the Mirror Universe before everything started to go wrong for her when she does.
Georgiou tries to make different decisions, subtly showing some of the compassion she learned while aboard Discovery in the prime timeline. That doesn't go over well in the mirror universe, and she winds up dead…only to wake up alive again on the planet with Burnham and Carl. Months passed for her in the Mirror Universe but mere moments for them.
It turns out Carl is the Guardian of Forever, the being from the classic Star Trek episode "The City on the Edge of Forever." Georgiou wasn't really in the Mirror Universe. The Guardian was testing her to see if she was worth saving. Having found her worthy, the Guardian agrees to send Georgiou back into the past, to a point where the Mirror Universe and the prime timeline had not yet diverged. Georgiou says her goodbyes to Michael Burnham and walks through the Guardian's portal, presumably ending her time on Star Trek: Discovery.
This is the second time that Discovery has said goodbye to Georgiou. Michelle Yeoh played the prime timeline's Georgiou in the first two episodes of Star Trek: Discovery. She died in the second episode, "Battle at the Binary Stars."
This doesn't mean it's the last we'll see of Georgiou. CBS is working on a Section 31 spinoff of Discovery, which Yeoh will lead as Georgiou. There's been little word on the show during the pandemic, but it was meant to film its pilot immediately after Discovery's third season wrapped.
New Star Trek: Discovery episodes debut Thursdays on CBS All Access.