Burnham meets with Emperor Georgiou, while Stamets and his alternate self try to escape the mycelial network.
Tropes in this episode include:
- All for Nothing: The data on the Defiant proves completely useless. Not only is the file heavily redacted, but what little info is still there doesn't provide a way home. Georgiou further confirms the futility of using the same method as the Defiant by telling Burnham that the interphasic rift also made the crew go insane and kill each other.
- As You Know: Burnham gives Lorca an analgesic that he specifically asked her for, and then tells him that it "should help you withstand the agonizers," which is the only reason he would have asked for it in the first place.
- Bad Liar: Mirror Stamets, according to his prime counterpart.Stamets: Tell me why you can't stop clawing at your arm.
Mirror Stamets: It's nothing.
Stamets: It's nice to know I'm a terrible liar in every universe. (sees Mirror Stamets' arm) Is that... Armillaria ostoyae?
Mirror Stamets: It's the network. It's taking me over. I've been here too long.
- Bottled Heroic Resolve: Burnham injects Lorca with an analgesic she developed that should help him resist the agonizers more effectively. It works for when Lorca ends up Playing Possum later.
- Buy Them Off: The Emperor offers Lord Eling the governorship of Andoria if he keeps quiet about his knowledge of Burnham being from the Prime Universe. And if he also cleans up the bodies.
- Chekhov's Gun: Georgiou's Starfleet insignia, which Burnham took from Kol, turns out to be very useful, as she uses it to prove to Mirror Georgiou that she's from another universe. Indeed, Mirror Georgiou confirms the findings by scanning the object's quantum signature.
- Cliffhanger: The episode ends after its revealed that the Lorca Michael and the rest of the cast have been taking orders from is from the Mirror Universe and he used everyone to get back to his universe to make another attempt to claim the Emperors throne.
- Conveniently Interrupted Document: The intel about the Defiant is heavily redacted, including the specific coordinates of where the ship fell through interphasic space.
- Cool Starship: The ISS Charon, a flying palace with a miniature star suspended in its structure.
- Cruel and Unusual Death: One of Lorca's crew is injected with DNA that causes his skin to combust before he slowly disintegrates.
- Deadly Disc: The weapon the Emperor uses to kill all of her advisors and guards (but one) is a little flying buzzsaw that propels itself through all of their heads within a few seconds. Presumably, its purpose is to protect her life in case of an attempt on it.
- Dead Person Conversation: Stamets spends a full scene with the recently-murdered Culber in the mycelial network.
- Death of Personality: Voq's and Tyler's personalities are merged together, with Tyler the nominal survivor, because Voq tried to tear his own body apart rather than live as a human.
- Death Wail: After eliminating Voq from Tyler's body, L'Rell performs the death roar.
- Evil All Along: Lorca was always morally ambiguous, but this episode reveals he's from the Mirror Universe and has been using his position to plot his eventual return and takeover.
- Evil Is Not Well-Lit: This episode explains and justifies the use of this trope in both Star Trek: Enterprise and the past few episodes: the Terrans, who embraced their flaws and created a tyrannical, racist empire, are more sensitive to light than the prime universe humans, who are still flawed but cooperate with multiple other species in a democratic government.
- Even Evil Has Loved Ones:
- Maddox is a mass murderer and brutal torturer. But he genuinely loved his sister Ava, and his vendetta against Lorca is about how the latter used her, leading to her death.
- Emperor Georgiou loved her adopted daughter, Mirror Burnham, until she and Mirror Lorca started a coup attempt against her.
- Famous Last Words: Voq's final words before he's excised from Tyler's body.Voq/Tyler: (in Klingonese) Kahless, give me light! Father, give me wisdom! Mother, give me drink! (in English) Brother, give me strength. Sister, give me family.
- Fighting from the Inside: Even though Voq has been awakened, Tyler briefly reasserts control.Tyler: (to Saru) Burnham, is she all right?
Saru: She's fine.
Tyler: Good. Saru. Help me, please. (starts screaming again)
- Finishing Stomp: After gloating a bit to Maddox, who just got his brain scrambled by a defibrillator, Lorca stomps his head in.
- Foreign-Language Tirade: Now that Voq has been awakened, he spends a full scene in Sickbay ranting in Klingon."Filthy humans! Let me die!...I will kill you all in T'Kuvma's name!"
- A Form You Are Comfortable With: The mycelial network takes the form of Discovery's halls so that Stamets has an easier time processing the experience.
- Freeze-Frame Bonus: In Stamets' Mental World, which has taken the form of a starship, there's a passing shot of a plaque which indicates he is onboard the USS Stamets.
- Genuine Imposter: Burnham has been passing Lorca off as his mirror counterpart since she went to the Shenzhou. As it turns out, he is his mirror counterpart.
- He Knows Too Much: After Burnham admits to being from the Prime Universe, Georgiou kills all of the Lords and guards present except Lord Eling, as knowledge of the other universe is highly classified. Eling gets to live because she needs someone to dispose of the bodies without asking questions. Plus, Georgiou makes him Governor of Andoria to buy his silence.
- Hufflepuff House: The Tellarites are the only one among the Federation's founding species that don't merit a mention in the Emperor's long string of titles. That said, the Terrans are extreme speciesists, so probably they felt that the Tellarites didn't warrant a mention—or the Tellarites were on the receiving end of an Inferred Holocaust instead of being conquered.
- I Ate WHAT?!: Having picked a Kelpian when prompted by Georgiou, Burnham has to work her damnedest not to be sick when she realises that Kelpian meat is being served to her as dinner—and she quite probably chose her meal like a lobster in a restaurant.
- Instant Waking Skills: Stamets gets back on his feet pretty quickly after being Asleep for Days. Mirror Stamets is an even more extreme example, given that he's been comatose for months.
- Internal Reveal:
- Burnham reveals her true identity to Mirror Georgiou, as Georgiou would have executed her as a traitor otherwise.
- Mirror Georgiou reveals to Burnham the fate of the Defiant's crew and the reason crossing over using interphasic space is a bad idea. Strangely, she doesn't reveal the role the Tholians played in getting the Defiant to cross over, though that may be to keep Burnham reliant on her help.
- I Will Punish Your Friend for Your Failure: Maddox brings in one of Lorca's crew and threatens to kill him very painfully unless Lorca says the name of Maddox's sister, whom he was involved with. When Lorca doesn't, Maddox kills the man.
- Literary Allusion Title: The title comes from Act I, Scene 7 of Macbeth: "I have no spur to prick the sides of my intent but only vaulting ambition, which o'erleaps itself and falls on the other."
- Mad Scientist: Mirror Stamets exploited the mycelial network to such an extent that it's now dying of some kind of corruption.
- Mercy Kill: Realising that a Klingon supremacist cannot exist in a human body, L'Rell is forced to excise Voq, leaving Tyler's personality in sole control of their body.
- My Sister Is Off-Limits!: Maddox's beef with Lorca is that he slept with his sister. And possibly killed her. That's why It's Personal for him.
- Oh, Crap!:
- Lord Eling looks like he will need a change of underwear when he sees the Emperor slaughter half a dozen of the high lords of the Empire plus a few guards in a instant, because she wants to keep a secret. Fortunately for him, she decides to bribe him into keeping quiet.
- Burnham realizing the truth about Lorca.Burnham: [to Georgiou] My so-called captain's not from my universe. He's from yours.
- Once More, with Clarity!: When Emperor Georgiou describes Lorca's Wife Husbandry of Mirror Burnham, prime Burnham recalls the things Lorca told her throughout the season, starting with "Context Is for Kings," only now with the horrifying realization that he was manipulating her into following him. She also sees that Emperor Georgiou is sensitive to light — and so is Lorca.Georgiou: He groomed you. He chose you.
Lorca: (flashback) I did choose you, but not for the reasons you think.
Georgiou: He told you that destiny brought you together.
Lorca: (flashback) Different universe, and yet somehow... the same people had a way to find each other. It's the strongest argument I've ever seen for the existence of destiny.
Georgiou: He said he'd cross time and space itself to take what was rightfully his.
Lorca: (flashback) Apparently the 133 jumps we've made filled in the gaps.
- Parental Substitute: Mirror Georgiou adopted Mirror Burnham her after the loss of her parents. This begs the question of whether Mirror Connor had a death wish when he tried to kill Burnham, knowing full well that there would be a reprisal.
- Playing Possum: As he's being tortured in the agonizer, Lorca collapses, seemingly dead. When Maddox tries to revive him, Lorca gets back up and overpowers him.
- P.O.V. Cam: We get a shot from Maddox's perspective as Lorca takes a boot to his face, this being the final shot of the episode.
- Pragmatic Villainy: The Emperor kills all the guards and lords present when Burnham says she is from the Prime Universe, but spares one and promotes him in exchange for his silence. She needs someone alive to cover up what really happened, and to dispose of the bodies.
- Red Herring: Mirror Georgiou tells Burnham that the interphasic anomaly that brought the USS Defiant into the Mirror Universe would be useless as a method of returning to the Prime Universe, firstly because the anomaly displaced the ship by over a century in time (presumably meaning that it would deposit the Discovery back in the timeframe of Star Trek: Enterprise, if it even worked at all), and secondly because it drove the entire crew of the Defiant into a homicidal rage.
- Retcon: In previous stories involving the Mirror Universe on assorted series, Terrans showed no particular sensitivity to bright light and it was never mentioned as one of their characteristics. On the other hand, their ships are always less well lit than Prime ships, and some have noticed Mirror Archer squinting on the bridge of the USS Defiant.
- Rewatch Bonus: Everything Lorca said and did throughout the season takes on a whole new meaning with The Reveal that he's been using Discovery and the spore drive to return to the Mirror Universe. Highlights include:
- Throughout "Context Is For Kings" and "The Butcher's Knife Cares Not For The Lamb's Cry", he was hell-bent on getting the spore drive functional.
- In "Lethe", he was terrified of Cornwell exposing him and taking Discovery away from him, which is why he wasn't in a hurry to rescue her from the Klingons.
- In "Into The Forest I Go", he and Stamets mused about the idea of traveling to alternate universes.
- Royal "We": When Burnham is to be executed.Georgiou: Captain Michael Burnham. We have sentenced you to death for crimes committed against the Terran throne. Do you have any last words before we collect our retribution?
- Say My Name: Captain Maddox tortures Lorca because of what Lorca did to his sister.Maddox: Say her name and beg for forgiveness!
- Shout-Out: The ISS Charon looks a bit like a Star Destroyer doesn't it?
- Title Drop:Mirror Georgiou: Your life will be long, Gabriel. And every single moment of it will be spent in our agonizers. A fair price to pay for your vaulting ambition.
- To Serve Man: Georgiou eats Kelpians as a delicacy. Burnham unfortunately has to partake in order to keep up the ruse.
- Traveling at the Speed of Plot: Nicely averted. Onboard her shuttle, Burnham sets course for the Charon, which the computer helpfully identifies as being 27 million kilometers away. She departs at Warp 1, the speed of light, 300,000 kilometers per second. The resulting trip should, and does, take exactly 90 seconds.
- Troll: Mirror Stamets can't resist messing with his prime counterpart.Prime Stamets: What is this? Am I dead? Is this the afterlife? Are you some sort of narcissistic Virgil leading me to judgment?
Mirror Stamets: Yes, Paul. You've been wrong about everything. There is a God, and she's very, very mad at you right now. (starts cracking up) I totally had you for a second there! You can't deny it! (laughing) You should've seen your face. I mean, our face. Hoo! That was classic.
- Try to Fit THAT on a Business Card!: Emperor Georgiou's full title is "Mother of the Fatherland, Overlord of Vulcan, Dominus of Qo'noS, Regina Andor, Emperor of the Terran Empire Philippa Georgiou Augustus Iaponius Centarius." Word of God is that "Iaponius" (Latin for "Japanese") is an homage to Empress Hoshi Sato, since Georgiou herself is Chinese-Malaysian.
- Treachery Cover-Up: Mirror Burnham was actually a traitor along with Lorca, and Georgiou covered up her involvement since she had adopted Burnham as a daughter.
- Weakened by the Light: Terrans in the Mirror Universe have an innate sensitivity to light, constituting their one physical difference from Prime Universe humans. This is the real reason why Lorca is sensitive to light, as he really is the Lorca of the Mirror Universe.
- Wham Episode: Lorca is actually from the Mirror Universe, and all his actions to this point were one long con to get back and take the Emperor's throne.
- Wham Line: Maddox has been torturing Lorca to get him to say his sister's name, which Lorca shouldn't know. When Burnham realizes his true identity, however:Lorca: Ava. Her name was Ava. And I liked her. But you know how it is. Somebody better came along.
- Wham Shot: Stamets and Tilly open the cultivation bay to find almost all of their fungi are dead, leaving them with no spores for the drive system.