Unification III (episode)
While grappling with the fallout of her recent actions, and what her future might hold, Burnham agrees to represent the Federation in an intense debate about the release of politically sensitive – but highly valuable – Burn data.

Summary

Teaser 
In a personal log entry, Commander Michael Burnham describes feeling uncertain about whether she still fits in on  after her year alone in the future. While she is still committed to the Federation and her friends, she feels distant and knows she will not be at peace until she discovers what caused the Burn, which she may not be able to do aboard Discovery. Burnham enters the ship’s shuttle bay, where Cleveland Booker’s ship is stowed, and beams aboard where she finds comfort in Booker's arms. Afterward, lying in bed, Booker asks when they are leaving Discovery and remarks on the awkwardness of his living situation inside Discoverys shuttle bay and among a crew that does not know "what to make of [him]." Booker asks if Burnham has always focused so closely on major mysteries such as the Burn. She replies that Spock similarly observed that she takes responsibility "for everything". Booker remarks that he and Spock could have bonded over Burnham's "endearing messianic complex."

Later, Burnham approaches Ensign Sylvia Tilly in a science lab and notes that Captain Saru demoted her from her position as first officer. Tilly says that Burnham put her in a "really awful situation" with Saru and Admiral Charles Vance by leaving on a clandestine mission to Hunhau. Burnham says it would have been difficult had she told Tilly, who retorts that it should have been her choice. Burnham apologizes but says she had to go and reveals she feels distant from the crew. Changing subjects, Tilly tells her that the first black box that she had previously obtained, off of the , lost contact one one-millionth of a second before the Gav'Nor, which had been a thousand light years away at the time. The computer is still analyzing the third recorder, from the , that was obtained by Booker on Hunhau.

Tilly notes that in three-dimensional space, the three points still leave a massive area in which the Burn could have originated, meaning more clues will be needed to narrow the search. Burnham tells her about an experiment she came across in Federation database files called SB-19. SB-19 involved sensors spread across thousands of light years of subspace and were present when the Burn occurred. Tilly informs Burnham that SB-19 reported no findings. Burnham states that either the sensors didn't record anything, to which Tilly asserts is unlikely, or that SB-19 did not make its results public. Tilly posits that Vance may have access, though Burnham reminds her that he is not her "biggest fan" at the moment, but then Tilly reminds her that solving this mystery is bigger than everything, including interpersonal politics. After a pause, Tilly wonders aloud what she would have done if Burnham had not returned from Hunhau. Before she can respond, the computer reveals that the Giacconi lost contact seven one-millionths of a microsecond after the Yelchin, confirming that the Burn did not occur across the galaxy at precisely the same time.

Aboard Federation Headquarters, Vance is shocked at the news. Burnham asks him about SB-19. He says the Federation does not have access to the data because it is held by a former member world: , which now goes by the name Ni'Var after many Romulans settled there alongside the Vulcans. Vance explains to the stunned Burnham and Saru that although the Vulcans and Romulans had long been enemies, Spock late in his life launched an effort to reunify the two peoples, an effort fulfilled centuries after his death. Saru says the Vulcans typically shared scientific data, but Vance reveals Ni'Var left the Federation a century prior.

Act One 
Burnham insists that the Vulcans would never abandon the Federation and is quick to blame the Romulans. However, Vance recalls that it was the Romulans, not the Vulcans, who wanted to remain a part of the Federation. He describes how at the time the Federation was running short on dilithium. Ni'Var had been working on a new system to transport ships across thousands of light years instantly, similar to the spore drive. Ni'Var scientists felt the new technology was too dangerous and sought to end the program, but it was the most promising solution and the Federation ordered them to continue. The planet's scientists felt that SB-19 somehow caused the Burn and, feeling they had been forced to cause it, left the Federation. Vance says scientific evidence would be unlikely to sway them – but that sending Burnham, Spock's sister, as the Federation's representative may open the door. Burnham reveals that she may not be able to "genuinely represent the Federation right now," but Vance orders her to act anyway.

Back aboard Discovery, Burnham thinks about her last moments talking to Spock before she left for the future, in which she urged him to accept those who reached out to him. In her quarters, she and Booker watch a recording of Spock from stardate 45825 held in the classified archives of Jean-Luc Picard in which Spock says that Vulcans and Romulans must either learn to live with enmity or find a way to change it and that he must help. After the recording ends, Burnham tells Booker she never allowed herself to find out what had become of her brother in the past. Booker jests that they are both "chronic overachievers" but notes that her complex relationship with the future could make her the perfect person for the job.

In his ready room, Saru asks Tilly to serve as acting first officer until he decides on a replacement, stunning Tilly. He notes her lack of experience, but Saru says he has watched her rise to the occasion on their missions in the future and says she will put the needs of Starfleet and the Federation ahead of her own wishes. He tells her to take a day to think about the offer.

Discovery uses the spore drive to jump to Lagrange point 1 of Ni'Var, where they are greeted by a hologram of President T'Rina. She is impressed by Burnham's credentials as Spock's sister and remarks that she wishes he could see the fruits of his labor for reunification, to which Burnham remarks he would find it "fascinating." T'Rina reveals that SB-19 is an issue of significant cultural sensitivity for Ni'Var; the planet still struggles with reunification, which was made more difficult by the Burn, and Burnham's inquiry could worsen the situation, T'Rina says. She denies the Federation's request to access the SB-19 data. However, Burnham, citing her rights as a graduate of the Vulcan Science Academy, invokes T'Kal-in-ket. After a tense moment, T'Rina says she will convene a Quorum and ends her transmission. Burnham reveals the ceremony is a "philosophical process designed to unearth deep truths", a key part of Vulcan's scientific advancement since the age of Surak. Once invoked, she cannot be denied, meaning Burnham has forced T'Rina's hand.

T'Rina beams aboard Discovery with the three members of the Quorum who will hear Burnham's case. T'Rina tells Burnham that her shalankhkai, the ancient Romulan designation for an advocate known to Vulcans as a sha-set, will arrive in a moment. Only sisters from the Qowat Milat can serve in that role, T'Rina notes, explaining that the sect's members "live and die by the precept of absolute candor." The Qowat Milat were essential to the reunification effort and help maintain healthy discourse on Ni'Var. Burnham apologizes for forcing T'Rina's hand, and she replies that a classic tactic in T'Kal-in-ket is to assail the credibility of the challenger. Burnham's failure would necessarily damage Spock's reputation and Ni'Var society, T'Rina says. She leaves with Saru. Burnham's advocate beams aboard, and Burnham is shocked to learn it is her mother, Gabrielle Burnham. They tearfully embrace.

Act Two 
Saru tells T'Rina that while Discoverys origins in the past are kept secret even from some in Starfleet, they revealed the ship's true history to Ni'Var because there was no other way to explain Burnham's presence. As they watch a sunrise over Ni'Var, Saru tells her he is troubled that the Federation is weakened but heartened that the remaining members are committed to its values. He reveals he hopes their visit will open new channels of diplomacy with Ni'Var, although T'Rina says their issues with the Federation extended well beyond SB-19.

Gabrielle tells Burnham that she never made it to Terralysium, instead finding herself back on Essof IV after she was held there briefly by the Discovery crew. Colonists delivered her to the Qowat Milat, which healed her. Gabrielle also observes that Burnham appears lost, and her daughter admits to learning about and enjoying a different way of life during her year alone in the future. Burnham also wonders whether she still fits in on Discovery but that she knows she is right about the Burn and can convince the Quorum to release the data. Gabrielle describes the three Quorum members: N'Raj is a "Romulan elder who longs for greater self-governance"; V'Kir is the youthful leader of a sect of Vulcan purists; and Shira is a Romulo-Vulcan "trying to forge a new path." Burnham feels her best strategy is to appeal to V'Kir, as a Vulcan purist will respond to logic. Gabrielle responds that Burnham is entering the process with "a lot of blind spots."

T'Rina explains to Saru that the pre-Burn dilithium shortage was caused in part by the sheer size of the Federation, which in turn pushed member worlds beyond their capacity or comfort for solutions. Saru replies that the greatest lessons are learned when the heaviest price is paid, and that the loss of Ni'Var as a member means the Federation has paid dearly.

The T'Kal-in-ket begins, with dozens of Discovery crew and Ni'Var citizens observing. Shortly after Burnham begins speaking, V'Kir interrupts, saying they have already reviewed her data and found it lacking. He calls for an end to the proceedings. Burnham protests, saying she has newly-uncovered evidence that the Burn did not start at Ni'Var. V'Kir questions Burnham's data and says it cannot compare to data already collected by the Ni'Var Science Institute. Burnham asks why they have not shared that data, and Shira replies that it is sensitive and Ni'Var cannot risk giving it to the Federation.

N'Raj notes that feeling the burden of having caused the Burn has caused "great hardship" that could be lifted if Burnham can prove the Burn had another source, but V'Kir cites recent unrest in his home province to press the point that "knowledge in the wrong hands in a dangerous thing." He similarly attacks Shira, noting that many resources have been spent quashing insurgencies in Romulo-Vulcan regions.

Burnham retorts that Spock "would have found it illogical to sacrifice knowledge to avoid risk," which V'Kir dismisses as an emotional appeal. N'Raj says they must share the data if there is a chance they did not cause the Burn; Shira agrees, but questions Burnham's motives. Burnham says she seeks the truth, but is surprised to find her mother question whether her effort is for the Federation or herself. With no consensus, Gabrielle calls for a short adjournment.

In engineering, Tilly tells Lieutenant Commander Paul Stamets about Saru's request that she serve as acting first officer. He notes that would make her his superior officer, in position if not rank. Stamets says the idea of taking orders from Tilly is "deeply, deeply weird, almost disturbing," but is interrupted by Joann Owosekun, who has come to ask about recalibrations for Discoverys return jump. Tilly uses the distraction to leave.

Meanwhile, Burnham tells Gabrielle that V'Kir arrived on Discovery with his mind made up, and her mother responds that cooperating with Burnham is a step toward the Federation. Gabrielle reveals she does not believe Burnham has been as truthful with the Quorum since she did not share her concerns about her place on Discovery. Burnham asks her mother to vouch for her trustworthiness, but Gabrielle replies that based on what she has not told the Quorum, she cannot.

The proceedings resume. Burnham tells the trio that her data appears to show that SB-19 did not cause the Burn but that she cannot be certain, and humbly asks for their help. V'Kir responds that the SB-19 data "definitively concludes that the Burn started here." Shira notes that Ni'Var did not leave the Federation without great thought and says Burnham is asking that it will not use the SB-19 data to resume the original experiment. Burnham insists the Federation can be trusted, but Gabrielle calls her "cynical" and says her own personal history departs from her claim that the Federation's has Ni'Var's best interests at heart. Gabrielle notes that Burnham mutinied against Philippa Georgiou before the Battle of the Binary Stars in which Georgiou ultimately died. Gabrielle also notes Burnham was just demoted and has shared misgivings about her place on Discovery. How can they trust Burnham now, Gabrielle asks.

Act Three 
Addressing the Quorum, Gabrielle notes that while Burnham grew up on Vulcan, she is Human "through and through." She is thus governed by emotion and has sought to insinuate herself into important matters to fill an emotional void left by her being orphaned, which Gabrielle says made her vulnerable to manipulation by the Federation. Burnham admits she did not share everything, but forces Gabrielle to confirm that the Federation gave her purpose and a family, and that Discoverys crew risked their lives to save the future. Burnham and the crew, though flawed, still lived up to the Federation's best ideals, she confirms. Burnham asserts she is fighting for the greater good, but Gabrielle asks why she thus struggles with her place on the ship. Burnham posits it may be because "the stakes are so much higher now" and that she fears failure.

Gabrielle tells the Quorum that Burnham has now spoken truthfully, but V'Kir continues to resist. N'Raj threatens to share the data on behalf of Romulans, alarming T'Rina and the other observers and heightening the tension. The three bicker, but Burnham interjects that Spock would not want to break down the connections between their two cultures. To preserve the reunification, Burnham realizes she must withdraw the T'Kal-in-ket challenge. She says she instead will search for new data to share with Ni'Var. She leaves as the Discovery crew in attendance rise.

Act Four 
Gabrielle enters Burnham's quarters. Burnham quips that she "could have chosen a better time to do some parenting." Gabrielle says Burnham does not need to choose between who she was and who she has become. She also reveals that T'Rina, having observed the T'Kal-in-ket, decided trusting Burnham was worth the risk and had decided to share the data. Gabrielle says she plans to stay on Ni'Var but notes Burnham now knows where to find her, and they hug.

Tilly enters engineering to find the bridge crew, who urge her to accept the acting first officer position. Saru made the right choice because they would follow her anywhere, Stamets says. Burnham arrives and reveals she has the SB-19 data. She tells Tilly she does not need Burnham's blessing and reveals she will remain on Discovery.

In Saru's ready room, T'Rina says the experience differed from her expectations – a compliment. They agree to continue broader talks over time. T'Rina offers the traditional Vulcan salute and beams away.

Aboard his ship, as Grudge lounges nearby, Burnham and Booker contemplate their uncertain path forward together now that Burnham has decided to stay. They each say the other feels like home as Discovery travels away from Ni'Var.

Log entries 

"Personal log, supplemental. Even after a year of finding my way alone, I truly believed I could find a way to fit back into this uniform, onto this ship. Now I'm not so sure. I've become someone new; still just as committed to the Federation, to my friends – but there's a distance between us now. I know I'll never be at peace until I solve the Burn. But I don't know if I can do it from Discovery. This may not be my home anymore, and I don't know what that means or where it will lead me." – Michael Burnham

Memorable quotes 
"Closed minds have kept these two worlds apart for centuries. We can either choose to live with that enmity, or seek a way to change it. The union of the Vulcan and the Romulan people will not be achieved by politics or by diplomacy. But it will be achieved. Like the first Vulcans, these people are struggling through a new enlightenment. And it may take decades or even centuries for them to reach it, but they will reach it. And I must help."
- Spocks speech to Jean-Luc Picard on Romulus in 2368. ()

Background information

Production history 
 : Title publicly revealed

Title 
 This episode is the first one to be numbered as the third episode in a multi-episode story, and the first one to continue the episode numbering in its title from another Star Trek series (as it continues the Vulcan-Romulan reunification storyline from  and ).

Cast and characters 
 Wilson Cruz (Hugh Culber) and Rachael Ancheril (D. Nhan) are not credited and do not appear in this episode.

Continuity 
 This episode seemingly draws a conclusion to the actions began by Spock in the  namesake episodes  and , which were further explored in  and . Indeed, events of this episode replay Spock's speech about "closed minds [that] have kept these two worlds apart for centuries" from "Unification II" and present them as part of a record from circa stardate 45825.
 The Qowat Milat were introduced in the  episode .
 Burnham's graduation from the Vulcan Science Academy was previously referenced in , and on her personnel file in .
 Burnham notes that T'Kal-in-ket had been used since the time of Surak, where the  episode  had previously established that Surak lived during the 4th century.
 "Ni'Var", the new name for Vulcan, was previously used for the name of a Vulcan starship in the Enterprise episode . Ni var was a term coined circa  by linguist Dorothy Jones, who wrote the Dorothy and Myfanwy series of Star Trek stories for the fanzine T-Negative in the late 1960s and early 1970s. It literally means "two form" and was an art form practiced on Vulcan in which a subject was examined from two different viewpoints, or in terms of its having two different aspects or natures.
 Michael Burnham's mutiny against Captain Philippa Georgiou and the captain's death are from  and .

Reception

Links and references

Starring 
 Sonequa Martin-Green as Michael Burnham
 Doug Jones as Saru
 Anthony Rapp as Paul Stamets
 Mary Wiseman as Sylvia Tilly
And
 David Ajala as Cleveland "Book" Booker

Guest starring 
 Oded Fehr as Admiral Charles Vance
 Sonja Sohn as Gabrielle Burnham

Co-starring 
 Emily Coutts as Lt. Keyla Detmer
 Patrick Kwok-Choon as Lt. Gen Rhys
 Oyin Oladejo as Lt. Joann Owosekun
 Ronnie Rowe Jr. as Lt. R.A. Bryce
 Sara Mitich as Lt. Nilsson
 Julianne Grossman as Discovery computer (voice)
 Oliver Becker as N'Raj
 Stephanie Belding as Shira
 Emmanuel Kabongo as V'Kir
 Tara Rosling as President T'Rina

Uncredited co-stars 
 Arista Arhin as Young Michael Burnham 
 Avaah Blackwell as an Osnullus science officer
 Michelle Browne as Discovery bridge crewmember
 Nicole Dickinson as a Trial spectator
 J. Adam Huggins as a Discovery engineer
 Liam Hughes as Young Spock 
 Anthony Lake as a Trial spectator
 Pamela Mars as a Discovery bridge crewmember
 Taylor Martin as a Trial spectator
 John Mucciacito as a Discovery engineer
 Leonard Nimoy as Old Spock 
 Ethan Peck as Spock 
 Leeu as Grudge

Stand-in 
 Stacy-Ann Buchanan as stand-in for Sonequa Martin-Green

References 
042; 2258; 3089; 40 Eridani A; acting first officer; admiral; "all hands"; ambassador; analysis; apology; area; audience; ; Battle of the Binary Stars; black alert; black box (data recorder); Booker's ship; brother; ; captain; cargo bay; century; choice; circa; citizen; Command Training Program; ; coordinates; courage; daughter; day; debate; demotion; dilithium; diplomacy; dozen; duty; Earth; elder; emotion; enemy; ensign; Essof IV; Essof IV colonists; evidence; experience; experiment; fact; Federation; Federation database; Federation Diplomatic Corps; Federation Headquarters; Federation Headquarters fleet; Federation members; Federation Ni'Var starship; first officer; friend; Gav'Nor; ; ; hate; Hawaii; ; headline; home; homeworld; hug; hypothesis; IDIC; insubordination; insurgency; joy; kiss; Klingon; Lagrange point; laughter; leader; leadership; leave; lieutenant; light year; logic; long-range sensor; madam; maxim; mentor; messianic complex; Milky Way Galaxy; microsecond; millisecond; mother (mom); motive; mutiny; mycelial network; name; Ni'Var ancestors; Ni'Var; Ni'Var satellite; Ni'Var Science Institute; Ni'Var scientists; operations center; order; Osnullus; Peer; permission; personal log; phrase; ; politics; president; President of Ni'Var; propulsion system; protocol; proverb; province; public address system; Qowat Milat; Quorum; refresher; Remus; representative; reprimand; reunification; risk; Romulan; Romulo-Vulcan; Romulus; Sarek; Sarek's residence; SB-19; science; science lab; scientist; secret; sensor; shalankhkai; sha-set; shuttlebay; sister; size; space; species; spore drive; Starfleet; status report; storage bay; subatomic lensing; subspace; superior officer; Supernova of 2387; Surak; T'Kal-in-ket; tan qalanq; Temporal Accord; Terralysium; theory; three-dimensional space; torch; tribe; truth; two-dimensional space; vessel; Vulcan; Vulcan ancestors; Vulcan gong; Vulcan language; Vulcan purist; Vulcan salute; Vulcan Science Academy; Vulcan system; Way of Absolute Candor; window; wisdom; worker bee; wormhole;

External links 
 
 
 

DIS episodes
pl:Unification III
de:Wiedervereinigung Teil III