Captain "Killy" in the Mirror Universe on 'Star Trek: Discovery'

Star Trek: Discovery has a knack for going back to the well.

Not just within its own continuity. But the series plays fast and loose with Star Trek canon. The two-parter, ‘Terra Firma I and II,’ is oozing with Trek nostalgia. Historically, Star Trek: Discovery tends to fall off track when it engages in divergences from its main story. And somehow, with this two-part story, Discovery excels.

Somehow, Star Trek: Discovery managed to balance the Burn, a trip to the Mirror Universe, a reference to the Kelvin-verse, and a legacy character from The Original Series. All without breaking a sweat.

Georgiou and Burnham ready for a mission on 'Star Trek: Discovery'

The Plot

With a little help from Kovics (David Cronenberg), Culber (Wilson Cruz) discovers the ailment destroying Georgiou (Michelle Yeoh). The Mirror Georgiou is suffering from a slow, molecular breakdown. A combination of traveling from the Mirror to the Prime Universe coupled with a 930-year jump to the future is causing Georgiou’s molecules to destabilize. The Discovery‘s computer finds a solution on a remote planet in the Gamma Quadrant. Georgiou and Burnham (Sonequa Martin-Green) travel there and meet Carl (Paul Guilfoyle). A mysterious man in a bowler and reading a newspaper, Carl offers a literal door to Georgiou’s cure.

Georgiou passes through and finds herself back in the Mirror Universe. Approximately three years before the Discovery‘s incursion there in the first season. She’s greeted by the Mirror Tilly (Mary Wiseman), the captain of the I.S.S. Discovery. It’s the day that Lorca began an insurrection against the Emperor. And the day the Mirror Burnham tried to betray her. While Georgiou’s instincts are to correct the mistakes of the past with brutality, she finds more “civilized” ways to deal with unrest in her Empire.

Upon returning from the Mirror Universe, Carl reveals himself as the Guardian of Forever. The ancient time portal from the classic TOS episode, ‘City On The Edge Of Forever.’ After years being used as a tool in the Temporal Wars, the Guardian assumed a new form and transported to a remote corner of the galaxy. Despite a conclusion to Georgiou’s business in the Mirror Universe (creating an alternate Mirror Universe in the process), Georgiou’s molecules are still breaking down. The Guardian offers to send her back through time.  A period when there was less space between the Prime and Mirror Universes.

Meanwhile, back on the Discovery, Adira (Bel de Barrio) and Stamets (Anthony Rapp) show Saru (Doug Jones) and Admiral Vance (Oded Fehr) another clue to the Burn’s origin. A distress signal from a disabled Kelpian ship, trapped within a nebula. But the Emerald Chain threatens more unrest within Federation space.

Saru, Georgiou, and Burnham on 'Star Trek: Discovery'

The Performances

Finally, a story worthy of that signature Star Trek: Discovery overacting.

The most fun aspect of any Mirror Universe story is seeing the actors just go for it. Sonequa Martin-Green didn’t get a chance to play Evil Burnham the first time around. Here, she gets to go full-tilt. And for the first time since early in the season, Green seems like she’s having fun. The same is true of Mary Wiseman as Captain Tilly. Or Captain “Killy” as she’s affectionately known in the Mirror Universe. Wiseman absolutely gobbles up the scenery, not leaving a single crumb in her wake. She’s brutal, over-the-top, and borders on ridiculous. Which is completely appropriate for this story.

But the real story of this Star Trek: Discovery two-parter is Michelle Yeoh. All season long, Georgiou has had trouble adapting to the future. Here, Yeoh gets to run the emotional gauntlet. Her stubborn denial to accept Culber’s help eases into familiarity with her old universe. And then, the realization that she doesn’t have to murder everyone to right her past mistakes. The arc has been playing all season. And, in hindsight, Yeoh has played it perfectly every step of the way. Her Star Trek: Discovery swan song shows us the full range of her character. And of her acting chops.

Paul Guilfoyle is fun in his guest role as Carl/The Guardian. He’s a fun enigma in his first appearance, cracking bad jokes and talking in riddles. It makes his turn as the Guardian more worthwhile. After all, this could’ve been any sentient time portal. Why the Guardian? Guilfoyle’s explanation is delivered perfectly, and it enriches the story as a whole.

The crew investigates the Burn on 'Star Trek: Discovery'

Writing And Directing

To be fair, some of this Star Trek: Discovery two-parter was spoiled for me before seeing it. And I rolled my eyes. A lot. “Really? The Mirror Universe? Again? And the Guardian of Forever? Seriously?” It seems like a lot of fan service. There’s certainly a lot of that going around in streaming sci-fi these days.

But Discovery pulled off its big fan service trip every bit as well as The Mandalorian. And for the same reasons. Whereas the trip to the Mirror Universe in season one was a diversion that served absolutely no purpose, this one finally brings Georgiou’s arc to a close. The slow burn of Georgiou’s character finally burned down to the fuse in ‘Terra Firma.’ It was absolutely worth it.

Part I, written by Alan McElroy, is steeped in Trek lore. But it never runs away with the story. This is a character study from the jump, with just enough plot and red tape to keep things moving. In Part II, writer Kalinda Vasquez puts everything together. All without rushing the story. Every action has a consequence and a purpose to the overall story. There’s no wasted motion here, no fat to be trimmed. Every bit of this Star Trek: Discovery two-parter is there because it needs to be.

Part I and II’s respective directors Omar Madha and Chloe Domont put together another well-paced and action-packed Star Trek: Discovery adventure. The redress of the Discovery sets in the Mirror Universe are lush and lavish, heavy with reds and harsher lighting. Mirror Stamets’s ornate and over-the-top christening of Georgiou’s new flagship was especially good. The direction is just as tight as the story, with no wasted motion and no wasted scenes. Action scenes are brutal, reflecting the darker tone of the Mirror Universe.

Ultimately, this is Georgiou’s story. Season One got lost with the pageantry of the Mirror Universe. It placed ridiculous emphasis on style over substance, hoping the fans would say, “Isn’t it cool we’re in the Mirror Universe?” Here, Star Trek: Discovery puts all of the puzzle pieces together.

Emperor Georgiou back in the Mirror Universe on 'Star Trek: Discovery'

The Breakdown

There’s a reason this is the strongest season of Star Trek: Discovery to date. And the ‘Terra Firma’ two-parter is full of the reasons why.

It would have been very easy to just do a Mirror Universe episode. A diversion, much like Star Trek: Enterprise did in its final season. But the writers have learned their lessons from past seasons. And from past nostalgia trips. There has to be something there to enrich the characters and the story. With this two-parter, Star Trek: Discovery put it all together.

There are only three episodes left this season. And for the first time in the New Trek, it doesn’t feel like they’re racing to the finish. Star Trek: Discovery can take its time for once. What a refreshing thing to reflect upon.

New episodes of Star Trek: Discovery stream Thursdays on CBS All Access.

All images courtesy of

'Star Trek: Discovery' - Terra Firma, Parts I and II








Entertainment Value



  • Georgiou comes full-circle.
  • Green and Wiseman chewing the scenery.
  • Resisting the urge to be "just another Mirror Universe story."
  • Carl.


  • So long, Emperor Georgiou. We JUST got to know you.