Warning: SPOILERS for Star Trek: Discovery's season 3 finale.
The Star Trek: Discovery season 3 ending dealt a final blow to Osyraa's (Janet Kidder) quest to destroy the United Federation of Planets and set up yet another new paradigm for the U.S.S. Discovery going into season 4. "That Hope Is You, Part 2" also concludes the macro story of Commander Michael Burnham (Sonequa Martin-Green) that began with her questioning her place in Starfleet and her purpose after arriving in the 32nd century in the season 3 premiere, "That Hope Is You, Part 1". By the end of the Star Trek: Discovery season 3 finale, Michael Burnham became the new Captain of the Discovery.
"That Hope Is You, Part 2" was a breakneck hour divided into three simultaneous plots. Aboard the Discovery, which was under the control of the Emerald Chain, Michael freed herself and Cleveland Booker (David Ajala) from captivity and fought their way through the starship, Die Hard-style. Burnham contacted the remaining bridge crew led by Ensign Sylvia Tilly (Mary Wiseman); although their oxygen was depleted, Michael ordered them to disable one of Discovery's warp nacelles to prevent Osyraa's scape from the Federation fleet in hot pursuit, including ships from Ni'Var Michael summoned. Commander Burnham's goal was to get to Discovery's data core and reboot the ship to rid it of the Emerald Chain's control. In the process, Michael battled Osyraa and she killed the Orion leader of the Emerald Chain.
However, Osyraa's flagship, the Viridian, swallowed Discovery and trapped it. After she beamed Osyraa's Regulators off of the ship - Book killed their leader, Zareh (Jake Webber) - Michael's plan was to eject and detonate the warp core so they could escape and rescue Captain Saru (Doug Jones), Dr. Hugh Culber (Wilson Cruz), and Adira (Blu del Barrio) from the Verubin Nebula. Invigilator Aurellio (Kenneth Mitchell) theorized that Book's empathic powers would allow him to interface with the spore drive. Tilly yielded command of the ship to Burnham and Michael's gamble paid off as Discovery was able to jump to the Verubin Nebula in order to save their friends while the ejected warp core annihilated the Emerald Chain's starship.
Meanwhile, Saru was able to form a connection with Su'Kal (Bill Irwin), the child-like Kelpien who was living alone in the Verubin Nebula and inadvertently caused The Burn 125 years ago. Discovery's crew was able to show Su'Kal how he caused The Burn but that he is blameless because it happened due to his shock over the death of his mother, Dr. Issa (Hannah Spear). But the final minutes of Star Trek: Discovery's season 3 extremely busy and action-packed finale paid off the major storylines of season 3 and significantly reset the series going into season 4.
How & Why Michael Burnham Became The New Captain Of Discovery
Michael Burnham went from feeling like she wanted to quit Starfleet altogether to finally achieving the rank of Captain in Star Trek: Discovery season 3. Burnham's promotion capped off a tumultuous season where she flamed out as Captain Saru's First Officer and went rogue several times in order to accomplish missions outside of Starfleet regulations. However, it was Burnham's renegade attitude and tactics that saved the day against Osyraa in Star Trek: Discovery's season 3 finale, and she out-strategized and outfought her Orion captors to regain control of her starship, save her crew, and defeat the Emerald Chain.
The seeds for Michael's newfound Captaincy were actually planted by her mentor and frenemy, Emperor Philippa Georgiou (Michelle Yeoh), at the end of season 3, episode 10, "Terra Firma, Part 2". Before she used the Guardian of Forever to permanently leave the 32nd century, Georgiou reminded Michael that she deserves to be Captain and that Burnham is greater than she realizes. In the next episode, "Su'Kal", Burnham questioned whether Captain Saru was emotionally compromised by finding another Kelpien in the Verubin Nebula and Michael took it upon herself to rescue Discovery when it was captured by the Emerald Chain.
Ultimately, Michael's promotion as a reward for saving the Federation follows the tried-and-true Star Trek model of being recognized for outstanding acts of heroism above and beyond. The Kelvin timeline's James T. Kirk (Chris Pine) became Captain of the Enterprise in J.J. Abrams' Star Trek 2009 under similar circumstances, and the Prime Universe's Kirk also avoided court-martial and was given command of the Enterprise after he saved the Earth in Star Trek IV: The Voyage Home. Michael Burnham's macro story was always destined to end with her as Captain of the Discovery but how long she can keep command before being broken once more for insubordination is a question for Star Trek: Discovery season 4.
Captain Burnham looks like she is maintaining Discovery's heroic bridge crew in their usual positions and she is retaining Sylvia Tilly as her First Officer. It remains to be seen if Tilly will receive a promotion from Ensign to Lieutenant in Star Trek: Discovery season 4. The entire Discovery crew was also upgraded to wearing Starfleet's 32nd century grey uniforms so they've been fully accepted and integrated after they saved the Federation. The sphere data (Annabelle Wallis) also remains a part of the ship, though it appears to now be housed in the DOT-23 repair droids. Lastly, unlike Saru, Captain Burnham was quick to pick a Picard-like personal catchphrase: "Let's fly!"
What's Next For Captain Saru After Discovery Season 3
The exemplary Saru becoming Captain in Star Trek: Discovery season 3 was long overdue and seemed to signal the end of the bizarre game of musical captain's chair that the series has played since season 1, so it's a little disappointing to see him relinquish command before Star Trek: Discovery season 3 was over. But the writing was on the wall for Saru's time as Captain when he was sidelined in the Verubin Nebula in "Su'Kal" and played no role in the struggle to save the Federation from Osyraa.
However, the seeds for Saru ultimately giving up Discovery's Captain's chair were planted in season 3's final few episodes as Admiral Vance (Oded Fehr) began to question his judgment after a Kelpien ship was found stranded in the Verubin Nebula. Saru hadn't interacted with the Kelpiens since Star Trek: Discovery season 2 and saying goodbye to his sister Siranna (Hannah Spear) forever hurt him more than he admitted and kept him from contacting Kaminar in the 32nd century. In truth, Saru was long overdue for a homecoming, and he returned to Kaminar to help Su'Kal start a new life as well as reconnect with his people. Saru is a core Star Trek: Discovery character and he will return in season 4, but will he become Captain of his starship again?
The Federation Has Dilithium & New Members Again
Michael Burnham and Discovery's mission to learn the cause of The Burn and rebuild the Federation was achieved. The dilithium nursery planet in the Verubin Nebula was kept safe from the Emerald Chain, which fractured after the death of Osyraa, and the Federation has begun to mine and distribute the vital mineral to its member worlds. This means warp travel will return to the galaxy and allow interstellar trade to resume. As for Admiral Vance, Starfleet's Commander-in-Chief also found a new hope from Discovery's heroism after spending too many bleak years managing what was left of the Federation and just trying to maintain the volatile and hopeless post-Burn status quo.
On a more symbolic note, the Federation 'solving' its dilithium crisis and defeating the Emerald Chain repositions it as the hope of the galaxy once more, and this has encouraged planets that exited the Federation, like Trill, to rejoin, with Ni'Var also in negotiations. The Federation only had 38 member worlds in Star Trek: Discovery season 3, down from 350 at its apex, so there's no telling how many planets will comprise the resurgent United Federation of Planets in season 4. It was also heartwarming to see Lt. Aditya Sahil (Adil Hussain), whom Michael commissioned in Star Trek: Discovery season 3's premiere, take his rightful place in the Federation.
Book Can Be Spore Drive Navigator (What Does This Mean For Stamets?)
As a Kwejian, Book's natural empath abilities allowed him to connect with the mycelial network and become the spore displacement hub drive's navigator. This gives Michael's husky boyfriend the purpose aboard Discovery he'd been looking for - and it doesn't hurt that the new Captain is in love with him. Book also solves an ongoing problem of finding a replacement for Lt. Commander Paul Stamets (Anthony Rapp), who used to be the only way to interface with the spore drive.
However, where this all leaves Stamets is the question. Paul remains hurt and furious with Michael for ignoring his pleas to save Culber and Adira from the Nebula and forcibly banishing Stamets from Discovery - even though it was necessary so that Osyraa couldn't use the spore drive. Stamets isn't one to forgive or forget easily and it creates the question of whether he'll bury the hatchet with Michael or possibly choose to leave Discovery for another Starfleet posting in season 4.
Culber Promised Grey He Would Be "Seen"
Star Trek: Discovery season 3 made history by introducing Adira and Gray Tal (Ian Alexander), the franchise's first non-binary and transgender characters. Adira formed a new family unit with Stamets and Culber, but the wrinkle was Gray, who died and is part of the Tal symbiont but could still manifest himself to be seen by Adira. The Kelpien holodeck aboard the Khi'eth allowed Gray to be seen by Culber and the others in holographic form (albeit as a Vulcan), and Discovery's doctor promised Gray that he'd find a way for him to be seen permanently. Whether that will entail a hologram, a synthetic body like in Star Trek: Picard or another innovation is something to look forward to in Star Trek: Discovery season 4. Gray being "seen" is also clearly a metaphor for Star Trek: Discovery bringing important LGBTQ representation to the venerable franchise.
Star Trek: Discovery Season 3 Was About Communication
Star Trek: Discovery season 3's finale ended with an inspiring quote from Star Trek's late creator Gene Roddenberry that summarized the season's theme of communication. The yearning for communication was embodied by Adiya Sahil, who waited alone for 40 years to speak to someone from Starfleet until Michael Burnham met him in "That Hope Is You, Part 1". The Burn broke the galaxy apart and isolated planets and civilizations from each other, which allowed fear and ignorance to spread and evil, opportunistic forces like Osyraa to capitalize and seize power. The Federation itself succumbed to the post-Burn reality and couldn't protect or educate its own member worlds.
Just as the best episodes of Star Trek offer a mirror to the real world, Star Trek: Discovery season 3 aired in the midst of the COVID-19 pandemic with the isolationist 32nd-century galaxy inadvertently reflecting life in 2020 gripped by the pandemic. But Discovery's underlying message of people working together, trusting each other, and striving towards creating a better, more hopeful future never seemed more relevant - and it starts with open and honest communication to find a common ground, as Burnham learned on Ni'Var in episode 7, "Unification III".
Star Trek: Discovery Season 4's New Mission
While there's no telling what new challenges and enemies Captain Burnham and the U.S.S. Discovery-A will find in Star Trek: Discovery season 4, in the short-term, the season 3 finale set up the thousand-year-old starship was the beacon of hope to the Federation. Thanks to its spore drive, Discovery can instantaneously deliver dilithium mined from the Verubin Nebula to the planets and starbases in desperate need, which will then galvanize warp travel and reconnect the Federation, making it whole again. By the time fans catch up with Burnham and her crew in Star Trek: Discovery season 4, the Federation could be a lot closer to how it was in the 23rd and 24th centuries.
Excitingly, the 32nd century remains a more dangerous and volatile time than the 23rd-century era Burnham and her crew left behind. While Star Trek: Discovery season 3 has updated the whereabouts of classic aliens like the Vulcans, the Romulans, and even the Cardassians and Bajorans, other major threats remain as big question marks, most significantly, the Klingons and the Borg. And although the door to return to the Mirror Universe seems shut for good, Emperor Georgiou was right that the Discovery's distant future is more "Terran" than the past of 930 years ago. Fans hope season 4 will explore the new final frontier even further, and by adopting the classic TOS theme by Alexander Courage over the closing credits, Star Trek: Discovery cements its status as the flagship of the entire Star Trek franchise.