(written from a Production point of view)
Burnham heads to the ISS Charon with a special "gift" for Emperor Georgiou. Back on-board the Discovery, Stamets gains clarity while trapped inside the mycelial network with his Terran counterpart and Saru asks for L'Rell's help to deal with Tyler.
Heading for the ISS Charon twenty-seven million kilometers away, Michael Burnham and Captain Gabriel Lorca depart on SHNZ 03 from the ISS Shenzhou. The shuttlecraft travels at warp 1 after Burnham engages the autopilot shortly after departure to attend to Lorca, who is sitting restrained at the back of the craft. Before Burnham and Lorca departed the Discovery, Commander Saru managed to decrypt the data on the USS Defiant and the data was transferred to a PADD Burnham has carried on board the shuttle. However, much of the data is redacted. The decrypted data reveals that the Defiant crossed over to the parallel universe through interphasic space, but the location of the spatial anomaly was removed. Lorca suggests that Burnham should look for the information in the original file, which is likely to be found in the imperial palace on board the Charon. Burnham appears to be hesitant about the idea, but decides to remain silent.
She takes out a hypospray containing a custom analgesic she prepared following Lorca's request. Burnham administers the analgesic on Lorca to numb his nervous system so that he feels less pain if he is punished by agonizers.
Sensing Burnham's hesitation about finding the missing information about the Defiant on the Charon, Lorca assures Burnham of her ability. Unconvinced, Burnham returns to her pilot seat. She reveals her fear of confronting Philippa Georgiou, who she is unable to distinguish from the former captain she betrayed. Lorca reminds her that Philippa Georgiou of her universe has died and describes Georgiou as a mere ghost. Burnham counters Lorca by asking whether he has ever been afraid of ghosts.
The conversation is interrupted as the shuttlecraft computer informs Burnham that it has reached the Charon's security perimeter. The shuttlecraft disengages the warp drive and approaches the imperial palace, revealing the hull of the much-larger Charon.
While still paralyzed, Lieutenant Paul Stamets' condition vastly improves after Cadet Sylvia Tilly began treating him with sporal therapy. In engineering, Tilly informs Saru excitedly about Stamets' improvement across all biological metrics, but Saru does not share her optimism: where the Defiant had entered the parallel universe remains unknown, and Stamets' condition is not improving quickly enough to assist the Discovery crew to return to their universe using the spore drive. Saru is then asked to report to the sickbay. Before leaving, Saru asks Tilly to take charge of curing Stamets.
Inside the mycelial network, Stamets encounters his counterpart native to the other universe. Not recognizing that he is inside the network, Stamets asks his counterpart if he is experiencing an afterlife. The other Stamets jokes about Stamets being wrong about the existence of a god and for that reason he is very angry. After being amused by Stamets' initial confusion, the other Stamets reveals their true location.
The pair introduce themselves and shake hands. Then in a white flash, they find themselves inside the USS Stamets, an illusory starship that the mycelial network created to resemble the Discovery to make Stamets feel more at home. While walking through the network-constructed corridors, the other Stamets explains that he is an astromycologist working on board the Charon. An accident with his research has trapped his neural energy inside the network, while his physical body is in a catatonic state. It is revealed that the images Stamets has been seeing while traveling on the mycelial network were attempts by the other Stamets to make contact, so that he could escape the network himself. While trying to locate the network's exit, the pair encounter a network corruption. Before the corruption could reach them, they escape to engineering, where they believe the exit to be located.
Meanwhile in the imperial palace, Emperor Georgiou receives Burnham and Lorca. Georgiou tells Burnham that she did not expect to see her alive. She invites Burnham to choose a Kelpien standing on the side of the court. The three Kelpiens turn and look at Burnham blankly while Burnham looks back at them with puzzled eyes. Georgiou senses Burnham's confusion and tells Burnham that she should know what to look for in a Kelpien. One of the Kelpiens tilts his head and makes a clicking sound. Burnham decides to choose him. The Kelpien is then escorted away. After the confusing affair, Burnham collects herself and presents Georgiou with the "gift" of Lorca. Lorca refuses to bow to Georgiou and is beaten with a scepter, following which he collapses on the floor. Georgiou orders Lorca to be placed in agonizers for the rest of his life. Lorca was carried away to brig C as per the orders of Captain Maddox. After the Kelpiens and Lorca are dismissed, Georgiou finally welcomes Burnham and expresses that she is happy Burnham has not died hunting for Lorca. She invites Burnham to dinner as she caresses Burnham's face and calls her "dear daughter".
Ash Tyler is resisting sedation in sickbay. The doctor is unsure how to treat him, and confirms the state of his personality. Focusing on Saru, he calms down enough to ask about Burnham and to ask Saru to help him. He refuses.
While Lorca continues be tortured, Georgiou and Burnham share a meal prepared by the imperial chef. When Burnham tells Georgiou that the food is delicious, the emperor reveals that they have been eating Kelpien. Immediately disgusted, Burnham was fed a threat ganglia by Georgiou on a pair of chopsticks. Burnham reached her head forward and hesitantly allowed the ganglia to enter her mouth. She forced the ganglia down her throat. Burnham quickly learns that her counterpart in the mirror universe is adopted and given education by Georgiou. Georgiou confronts her on being soft and asks her why she hunted Lorca. When she doesn't get the reply she expected, she reveals she knew Burnham conspired with Lorca and takes a knife to her neck. Burnham then fails to call her "mother" as she usually did, which prompts Georgiou to sentence her to death.
In the mycelial network, Stamets shows his counterpart some data on his experiments with the spores, and shows him his arms. He then sees Culber and immediately goes after him, despite his counterpart's calls that it's an illusion.
Georgiou sentences Burnham in front of her captains. Burnham gives up the plan, admitting she is from another universe and giving proof from her uniform. Georgiou takes from her uniform her own counterpart's badge. Burnham continues to explain the other universe. Suddenly, Georgiou picks up a device and triggers it, immediately killing all but one of her captains and swearing the remaining one to secrecy.
Saru goes to L'Rell, gives her food and asks about Tyler. L'Rell is proud, saying that he has "awoken" and is a devoted warrior that will light the way to victory. Saru then explains where they are, that, there, the war is over and they are both in jeopardy. He's hoping to get some cooperation from her. She relents, explaining what they did to Ash Tyler and Voq, and that Voq accepted his suffering.
Stamets finds the network is modeling the Discovery for him. He pursues Culber and eventually reaches him in their quarters. The doors close and they talk. He confirms he's dead and not really in the network.
Burnham appeals to the Emperor to help them get back to their universe. Georgiou admits she knows about their universe through the logs of the USS Defiant, then denounces the Federation's ideals. She explains the crew of the Defiant went insane and killed each other. She wants to know how the Discovery made it to their universe, and they make a deal where Burnham gets help.
Saru shows L'Rell what Tyler is doing to himself and asks her to help him. She refuses and Saru then beams Tyler into the cell with her. She finally agrees, but only if it's her performing the operation.
Lorca is still being tortured when Maddox enters. Maddox proudly informs him they've rounded up all his loyalists. He then wants Lorca to admit what he did to Maddox' sister or else he'll kill another of his allies. He uses DNA of an exotic species to kill another man brought in.
L'Rell holds a device on Tyler's head, which eventually makes him calm down. He starts to describe his past in English, which makes her cry out as if he had died.
Stamets tells Culber he saw Tyler kill him. He then plays some music so his counterpart can't hear. They relive the memory of them at night telling each other about their day. Culber says Stamets was right about the network, but it's now in danger. He says Stamets' counterpart is corrupting the network, and Stamets must save it. Stamets is only partly interested, not wanting to say goodbye. He kisses Culber, and Culber tells him to "look for a clearing."
Stamets' counterpart then wakes up on the Charon while Stamets wakes up on the Discovery. He brings Tilly to the spore room, but it's too late.
Burnham calls Saru and has them come to the Charon. Georgiou then says she is reluctant to let Lorca go. Shockingly, she starts to argue that Lorca is actually the mirror-universe Lorca, noting his sensitivity to light. Burnham realizes she is right and the mirror Lorca has been impersonating his prime universe counterpart all along, needing Burnham to get to Georgiou.
Meanwhile, Lorca continues to refuse to comply with Maddox's request. Lorca fakes death and Maddox rushes to get him out of the agonizing booth, in fear that the Empress will punish him for killing her prisoner. Maddox uses defibrillators in an attempt to revive Lorca, but once he's is in a compromised position, Lorca attacks and ultimately kills Maddox by electrocution using the defibrillators and blunt force trauma to the head. Hovering over his body, Lorca says "Ava. Her name was Ava. And I liked her. But you know how it is. Somebody better came along," revealing he is in fact the Mirror Universe version of Lorca and genuinely forgot her name because she meant nothing to him.
"What are you afraid of?"
"You mean Emperor Georgiou."
"Logic tells me she's not the woman I betrayed, but this feels like a reckoning."
"Your Georgiou is dead. She's a ghost."
"Haven't you ever been afraid of a ghost?"
- - Gabriel Lorca and Michael Burnham
"What is this? Am I dead? Is this the afterlife? Are you some sort of narcissistic Virgil leading me to judgment?"
"Yes, Paul. You've been wrong about everything. There is a God, and she's very, very mad at you right now. ... (laughs) I totally had you for a second there. You can't deny it! Ha-ha! You should've seen your face. I mean... our... face. Hoo! That was classic."
"So... there is no God?"
"Well, you're still alive, so technically, who knows?"
- - Paul Stamets and Paul Stamets
"But if I'm not dead, who are you?"
"You. In my universe. Nice to meet you."
- - Paul Stamets and Paul Stamets
"The food is delicious, as always."
"No one prepares Kelpien like the Imperial chef. Here, have my ganglia. You deserve a treat."
- - Burnham and Emperor Georgiou share a meal
"Lord Eling, can you keep a secret?"
"Good. Clean this up. Never speak a word of it to anyone, and I'll make you governor of Andor."
- - Eling and Emperor Georgiou, after she kills all her lords except him
"You people are dangerous. 'The Federation.' I know it well from the Defiant's files. There is a reason why they're classified. 'Equality.' 'Freedom.' 'Cooperation.'"
"Cornerstones for successful cultures."
"Delusions that Terrans shed millennia ago. Destructive ideals that fuel rebellions, and I will not let you infect us again!"
- - Philippa Georgiou and Michael Burnham
"Tell me about your day."
"It was awful. My partner is dead, my life's work has been a waste, what I knew to be beautiful is hostile, and the mycelial network is hell."
- - Hugh Culber and Paul Stamets
"He needed me to get onto this ship; you wouldn't have let him on otherwise. […] He needed me to get to you. […] None of this was an accident. My so-called captain's not from my universe; he's from yours."
- - Burnham, telling Emperor Georgiou the horrible truth she has just realized about Captain Lorca
- This episode's title is a reference to the line "I have no spur to prick the sides of my intent but only vaulting ambition, which o'erleaps itself and falls on the other" from Act 1, Scene 7 of William Shakespeare's Macbeth. The title was chosen, as a deliberate reference to Macbeth, by writer Jordon Nardino while the installment was being developed. He later recalled, "I noticed, when we were breaking the episode – that's what we call writing the episode – that there were a lot of [plot threads in this installment] about people interacting with ghosts or visions from the past, as happens in Macbeth, so I sort of veered things that way [….] There's Burnham looking at Georgiou, there's L'Rell and Voq, there's Stamets and Culber, there's a banquet scene where someone is accused, by a ghost of a person that they killed, of their wrongdoing, and then, you've got Lorca reaching for the crown that he is trying to usurp, so… that's it." (AT: "Vaulting Ambition")
- During the breaking of the story for probably either this episode or the next one, Kirsten Beyer noticed – when she was in the Star Trek: Discovery writers' room with Bo Yeon Kim, Erika Lippoldt and Lisa Randolph – that it was a historically significant moment, due to there being an all-female writers' room. "I thought to myself, 'I believe this is the first time four women have sat around and decided what the future of Star Trek was with nobody else in the room,'" Beyer recalled. "It was a unique moment in history for sure, and I was very much aware of it." ("A Woman's Journey", DIS Season 1 & Blu-ray special features)
- The device which Emperor Georgiou uses to kill multiple Terran lords was originally to have been very different to how it ended up. "For the longest time," Jordon Nardino recalled, "it was just going to be like a rifle built into her […] throne [….] And then one day, my bosses, our showrunners, Aaron and Gretchen, take me into their office and they go… They're playing with a fidget spinner, which was our season one obsession, they were just everywhere and all the time, and they go, 'What if she just takes this off of her throne, and it flies around and kills everyone?' And I said, 'Okay, I'm in. Let's do it.'" (AT: "Vaulting Ambition")
Cast and characters
- Stamets actor Anthony Rapp thought that the way a fidget spinner inspired Emperor Georgiou's assassination device was "smart." (AT: "Vaulting Ambition")
- Culber actor Wilson Cruz described one of his scenes in this episode as "my favorite scene in my entire twenty-five-year career." (AT: "Despite Yourself")
- During the making of the episode, Hanelle M. Culpepper had a few conversations with actress Michelle Yeoh about how to differentiate the portrayals of the two Georgious and with Anthony Rapp about how to make his portrayals of the two versions of Stamets likewise different from each other. 
- The call sheets from the making of this episode referred to Tyler and Voq as being played by different actors, to ensure it wouldn't be leaked that they were the same person – namely, Shazad Latif. 
- Rather than Hanelle M. Culpepper requesting that she be considered to direct an episode of Star Trek: Discovery, the series' behind-the-scenes staff asked her to direct an installment for them. She believed this was because fellow director Olatunde Osunsanmi, who was a co-executive producer on the show at the time, recommended her. When Culpepper joined the project, there were many aspects of it which had already been designed, such as the ISS Charon. 
- To prepare for the task of filming the episode, Hanelle M. Culpepper watched a few of the first DIS installments, which were the show's only episodes that had been produced by then. She also had access to the episode scripts, so she read through those, and inquired into which movies the producers felt best conveyed the look and style they wanted for the show, which she proceeded to watch. Another resource she was given to aid her preparation was a book the series had compiled to demonstrate some of the design of the sets and other visual aspects of the show. 
- Many issues went into creating the sequence where Emperor Georgiou feeds Burnham a Kelpien threat ganglia. For example, the look of the ganglia changed significantly. "There were tons and tons and tons of memos and discussions and meetings about this Kelpien and seeing various designs and what color should a Kelpien be and, you know, the soup that it was in," Hanelle M. Culpepper laughed. The behind-the-scenes staff didn't want to use squid to represent the Kelpien meat because it had been used in a Klingon banquet scene in "The Butcher's Knife Cares Not for the Lamb's Cry". Furthermore, because Burnham actress Sonequa Martin-Green wasn't a meat-eater at the time of the episode's creation, the ganglia her character eats was ultimately created out of a vegetarian, gelatinous food material. It was totally tasteless and was slightly firmer than jello but was otherwise similar to that. "And I'm the one who asked, 'Could she please serve it with chopsticks?' so you could better see it," Culpepper added. She and Michelle Yeoh had a meeting in which the actress expressed enthusiasm about serving the ganglia with chopsticks. However, the creative personnel also briefly considered if the use of chopsticks might be offensive to Asian people. 
- There was some last-minute consideration to how Emperor Georgiou would fit in her throne. "In a panic, Gersha Phillips, our costume designer, called me from the dressing room where they were outfitting Michelle Yeoh in her cape. She had one scene where she wore this fantastic cape. And Gersha freaked out because we had a very specific throne that she thought, 'Oh, my God, the cape's not going to fit the throne,'" remembered Production Designer Tamara Deverell, with a laugh. "So I came running downstairs, met Michelle Yeoh, and said, 'Hi. I'm just gonna measure the width of you and your cape,' and… 'cause I understood Gersha's panic, and if it didn't work, Gersha would have to either hem in or I would have to hem out the throne room set, which was probably a little more difficult. So, that was kind of a fun interlacing of Gersha's vision and my vision working together, making sure she fit in her throne, which she did." ("Dress for Success", DIS Season 1 DVD & Blu-ray special features)
- Many of the scenes in this episode were shot using a Technodolly, which was a motion control dolly. This equipment was used to shoot all the scenes which featured the two versions of Stamets. Routinely, Culpepper set the dolly up and filmed multiple takes with it until she shot a take she was pleased with. That take was then locked in, Anthony Rapp changed his costume to represent the other version of his character, then played the same scene but in that role, and the dolly repeated the exact same motions as when it had filmed the locked-in take. Though Hanelle M. Culpepper found the Technodolly to be very handy, she also believed that the most challenging scenes in this episode, due to technical production problems with that apparatus, were definitely those that included shots in which Anthony Rapp had to play the two different versions of Stamets. "I ended up having rehearsals with Anthony, and Danny is his double, and so, thankfully, the production allowed us to have, you know, hours of rehearsal, really trying to work this all out. Colin was the D.P., so he and I [were] working out what would be a Technodolly, what would be something else [….] We had to bring our A-game but we still had to make it all work within our schedule. And then even working out the order of the shots per day, because you couldn't move the Technodolly," she laughed, "but you need them to change but it takes time to change them, so what would make the most sense? And then, for Anthony, just acting off of himself, you know, every time we did a blocking, we would do it at least two times. Basically, we would do it a few times with him in one role and then, before we committed to that, we would then maybe do it again with him in the other role, so that Danny could see how he would do it, because ultimately you want his double to act as he would act, not make Anthony be locked into decisions his double makes, so I think that was the hardest for, you know, Anthony." 
- During a break in filming the scene where Emperor Georgiou and Michael Burnham meet each for the first time, Gersha Phillips was on the set and attached the Emperor's sword to Michelle Yeoh's waist. ("Prop Me Up", DIS Season 1 DVD & Blu-ray special features)
- When the ganglia-eating scene was being filmed, Hanelle M. Culpepper promised Sonequa Martin-Green she wouldn't have to eat the fake ganglia for much longer. "I was like, 'I think only two more bites, I promise you; two more times you have to eat this stuff,'" Culpepper recalled, laughing. However, according to her, the scene, in general, wasn't very difficult to do. 
- The shot of water dripping from a faucet in the recreation of Stamets' quarters aboard the Discovery, inside the mycelial network, was a type of shot that Hanelle M. Culpepper very much liked to do, featuring something very big in the foreground and something happening in the background. 
- A prop L'Rell wears, while performing the reversal procedure on Tyler/Voq, was most likely the same prop as Tyler wears while extracting a cube from a debris field in the first act of "Despite Yourself". (AT: "Vaulting Ambition")
- In the sequence where Culber tells Stamets to open his eyes, Stamets then wakes up, with a close-up shot of his eyes opening, though the camera then widens to reveal that he is actually the Mirror Stamets. This sequence was directed by Hanelle M. Culpepper, and she enjoyed filming it. She described it as one of her favorite character reveals to do and noted, "That was a fun one to work out." 
- Hanelle M. Culpepper tried to make the reveal that Lorca was from the mirror universe "as fun as possible," in her own words. 
- This episode was the biggest CGI project which Hanelle M. Culpepper had ever done, as she had worked with green screen on many occasions but had never done a project where there was so much of it. A virtual reality system was used to allow her, as the sets were designed, to walk around them, in order to design her shots, enabling her to request such things as a window to be moved, elements of a set to be added, or a table to be flipped around. Regarding the tweaks to this episode's visuals, she stated, "Things kept changing as they figured out other things that were going to happen, not only in my episode but in future episodes that may have dictated that things change or color schemes and stuff like that." 
- The first shot in this episode's teaser, before it was filmed, was illustrated by a storyboard artist, who worked with Hanelle M. Culpepper from the first day she joined the project. "The opening scene, you know," she explained, "that is me telling the storyboard artist that I would love to start on the Terran logo and pull out, and then to see that we're on the shuttle, and then as it goes further away, I wanna see the ship behind them." 
- For a while, the shot of Burnham having to eat a Kelpien ganglia was to have been represented using a visual effects shot. 
- Hanelle M. Culpepper was unsure how much of the visual effects footage that she designed for the installment's teaser would remain in the episode. She found that generally most of it stayed. One shot she did design but was left out of the final cut took place when the shuttlecraft arrived at the Charon. The excised shot started with Burnham and Lorca turning to look at the vessel's super-mycelial reactor. "I had a shot behind their heads, where you see what you think is the sun, and as the camera slides out of the shuttle, it reveals that it's actually the orb of that giant ship," she explained. "And they ended up not doing it that way; they cut that, basically." 
- This episode had a lot of dialogue that Hanelle M. Culpepper trimmed down. This included, compared to the final version of the episode, even more talking in some scenes between Burnham and Emperor Georgiou as well as much more talking in one of the brig scenes with L'Rell and Saru. "I trimmed out what I felt was not necessary but kept the show moving," remarked Culpepper. Other edits were done by the producers. "And so," Culpepper added, "it felt like a lot of words came out." 
- Other footage which was deleted from this episode included an initial shot from a scene that involved the two versions of Stamets and was shot using a Technodolly, though not without difficulty. Recalling how the scene was filmed, Hanelle M. Culpepper remembered, "We had one day when we had – you know, a big day, of course – and the Technodolly was supposed to be most of the shots, and this would have been when he played against himself in his engineering lab, and the Technodolly just kept not wanting to work," she said, with a laugh. "They would figure out something, and then we would get ready to roll and call action, and then it would just shut down again, and finally it was like, 'You know, I think we'll just have to figure out a different way to shoot this,' 'cause it was getting on to be an hour into our day, waiting on this thing to decide to work. So, we started shooting it other ways and ultimately it worked. Finally, they figured out it was just, like, a little tiny technical thing that was, for some reason, tripping it and making it confused. And then the sad thing was I looked and I saw that they didn't even use the opening," she again laughed, "in that scene, which was part of the whole reason we did the Technodolly." 
- The ending of this episode was significantly altered in post-production. "They did a completely different scene. It was that… I had that [Lorca] was in the agonizer and the guard […] was torturing him, and also the guard gets killed at the end, and then Lorca goes and gives a speech, and then frees his guys. And so, they changed it […] so that he chokes the guard and then says, 'Her name was Ava,' and so that's your reveal, and then originally they had it, the reveal was more that, when he walked into the room where all the agonizers were, he announced he was back and had his speech." Based on this comment, it's likely that a deleted scene which is included in the DIS Season 1 DVD and Blu-ray but was purportedly part of the next episode, "What's Past Is Prologue", actually was originally the conclusion of this installment. 
Music and sound
- Composer Jeff Russo found it enjoyable to write the Kasseelian opera which is audible in this episode's soundtrack. "That was really super fun to do and super amazing," he enthused. 
- A few musical cues from this episode were released in the soundtrack collections Star Trek: Discovery - Season 1, Chapter 2 and Star Trek: Discovery - Season 1, Chapters 1 & 2. The first, entitled "I'll Take It from Here", is audible during the scene wherein Maddox kills Barlow in front of Lorca; the second cue is the aforementioned "Kasseelian Opera"; and the third cue, "The Lorca I Knew", is the final music that can be heard in the episode, accompanying Burnham's realization that the Lorca she has become familiar with is actually from the mirror universe.
- AT: "Vaulting Ambition" discusses the making of, and events in, this episode. The week before this installment was released, AT: "The Wolf Inside" debuted a clip from the conversation between Lorca and Burnham in this episode's teaser.
- A week prior to the release of this installment, Ted Sullivan described it as "a really interesting kind of exchange between these two brilliant but weird minds," referring to the two versions of Paul Stamets, and After Trek host Matt Mira responded that he "couldn't wait." Sullivan added, "And I think it's in an unusual setting." (AT: "The Wolf Inside")
- Hanelle M. Culpepper enjoyed seeing how much influence she did have on this episode's visual effects and approved of the installment's conclusion, stating she thought it was "quite impactful." "Even if you're a fan who's been figuring this all along, I think it's still satisfying to see the reveal and to be right, and so I hope that the fans all enjoyed that," she said, with a laugh. Culpepper was busy filming another production when this episode was aired. 
- Jonathan Frakes and Anthony Rapp watched the episode together in a room adjacent to the After Trek studio but without Matt Mira present. Both Frakes and Rapp found it was highly satisfying to see the reactions of Star Trek fans to the reveal that Lorca was from the mirror universe. "I was just on this Star Trek cruise […] and there were hardcore fans on there who are thrilled, and they feel vindicated, that the architect of the show has now revealed itself, and they suspected or they knew or they talked about it," commented Frakes. "I think it's been very clever and very successful." (AT: "Vaulting Ambition")
- Jonathan Frakes also thoroughly approved of the scene where Emperor Georgiou assassinates numerous lords of the Terran Empire, about which he raved, "That was fantastic [….] It was spectacular. Shot brilliantly, the visual effects were brilliant, the stunt work was great. That was wonderful." (AT: "Vaulting Ambition")
- When asked what he wanted fans to feel after watching this episode, Jordon Nardino stated, "Betrayed, lied to, tricked." Adopting a more serious demeanor, however, he continued, "No, I mean, really, I hope that they know what it feels like to have a Terran in their midst." (AT: "Vaulting Ambition")
- Aron Eisenberg commented that he "loved" that Lorca was revealed to be from the mirror universe. 
- Many fans seemed to think the most disgusting scene in all of Star Trek was the one where, in this episode, Burnham has to eat a Kelpien threat ganglia. 
- Matt Mira remarked that he considered "Vaulting Ambition" to be "a very apt title." Regarding the installment itself, he critiqued, "You have so much information to process at the end of this episode of, 'Ah. Well, okay. Stamets is back, the spores are gone, and Lorca's… been a real jerk this whole time,'" he stated, with a laugh. (AT: "Vaulting Ambition")
Continuity and trivia
- Aside from Star Trek: Short Treks, this is the shortest live-action episode of any Star Trek series ever, clocking in at just under thirty-eight minutes. It is the shortest episode since the final episode of Star Trek: The Animated Series aired in 1974. Hanelle M. Culpepper's edit of the episode was approximately somewhere between forty-four to forty-six minutes long. 
- This episode established that a Human Ash Tyler existed prior to the genetic transformation of Voq to assume the form of Ash Tyler.
- The technique of using the series' regular shipboard interiors to manifest a character's inner mental world in a comatose or altered state has been used several times in the franchise before, often complete with hallucinations of regular characters representing different themes or states of mind, such as in TNG: "Remember Me", "Birthright, Part I", "Phantasms", "Dark Page", DS9: "Distant Voices", "Extreme Measures", and VOY: "Barge of the Dead".
- The classified file on the Defiant referenced events seen in the Star Trek: Enterprise episode "In a Mirror, Darkly". The stardate mentioned in the report, 0141.7, is the earliest stardate known to date.
- It is revealed that, millennia ago, Terrans believed in equality, freedom, and cooperation but shed those beliefs. As of the 2250s, they believed these ideals were destructive delusions that bred rebellions.
- This is the first episode of the series in which neither Keyla Detmer nor her mirror universe counterpart appear.
- The use of parasitic lifeforms for punishment or other evil ends also figures into the films Star Trek II: The Wrath of Khan and Star Trek.
- Jonathan Frakes remarked that the moment when Emperor Georgiou uses a small spinning device as an assassination weapon is similar to Oddjob using a razor-bladed hat in the James Bond film Goldfinger. (AT: "Vaulting Ambition")
- Anthony Rapp observed that Saru's command style in this episode seems reminiscent of how Jean-Luc Picard would command, Rapp commenting about what Saru does, "I think that's what Picard would've done, I really do. It's very Picardian." (AT: "Vaulting Ambition")
- This episode revealed that the Gabriel Lorca seen thus far is actually a native of the mirror universe.
- Connected to this, this episode revealed that Humans and Terrans have only one biological difference: photosensitivity. In mirror universe episodes predating Discovery and following TOS: "Mirror, Mirror", Terran starships and habitats are noticeably darker than a Federation starship would be, and Jonathan Archer appears to squint while in the captain's chair of the USS Defiant in ENT: "In a Mirror, Darkly, Part II".
Links and references
- Sonequa Martin-Green as Michael Burnham
- Doug Jones as Saru
- Shazad Latif as Ash Tyler
- Anthony Rapp as Paul Stamets / Paul Stamets (mirror)
- Mary Wiseman as Sylvia Tilly
Special guest star
- Sam Asante as Senior Guard
- Jeremy Crittenden as Lord Eling
- Raven Dauda as Dr. Pollard
- Billy MacLellan as Barlow
- Dwain Murphy as Captain Maddox
- Tasia Valenza as Shenzhou Computer
- Marie Ward as Junior Guard
- Marcello Bezina as Lord
- Bobby Brown as Lord
- Tig Fong as Lord
- Dana Jones as Lord
- Marco Perretta as USS Discovery medical crewman
- Clayton Scott as Chosen Kelpien slave
- Chris Obi as T'Kuvma (archive footage)
- Unknown performers as
Andor; Archer, Jonathan; Armillaria ostoyae; Ava; beta waves; Buran, ISS; clearing; Charon, ISS; coma; Comtaxan parasite; Defiant, USS; dew; Dominus of Qo'noS; ganglia; glucose; Harlak; hellish; highway; infra-low waves; Enterprise, ISS; interphase; imperial chef; Mother of the Fatherland; NCC; Overlord of Vulcan; palace; phenomenon; Qo'noS; Regina Andor; San Francisco Fleet Yards; SHNZ 03; Stamets, USS; stardate; Tholian; Tholian asteroid dock; Tonnata VII; Tyler, Ash; Virgil; Vulcan; warship
- "Vaulting Ambition" at StarTrek.com, the official Star Trek website
- "Vaulting Ambition" at Memory Beta, the wiki for licensed Star Trek works
- "Discovering Mirror History" at MissionLogPodcast.com, a Roddenberry Star Trek podcast
|Mirror universe-related episodes|
|ENT: "In a Mirror, Darkly" • "In a Mirror, Darkly, Part II"|
|DIS: "Into the Forest I Go" • "Despite Yourself" • "The Wolf Inside" • "Vaulting Ambition" • "What's Past Is Prologue"|
|TOS: "Mirror, Mirror" • "The Tholian Web"|
|DS9: "Crossover" • "Through the Looking Glass" • "Shattered Mirror" • "Resurrection" • "The Emperor's New Cloak"|
| Previous episode:|
"The Wolf Inside"
| Star Trek: Discovery|
| Next episode:|
"What's Past Is Prologue"