- The U.S.S. Farragut NCC-1647 encounters a dikironium cloud creature at Tycho IV. The creature, which feeds on iron-based hemoglobin, kills two hundred people aboard the Farragut, including Captain GGarrovick. One of the survivors, Lieutenant James Kirk, blames himself for the disaster.
- Stardate 2136.8: While attending a crew party, Burnham and Tyler are called to the bridge to deal with an endangered space creature that the Discovery has come across. When the creature is brought aboard, it is revealed to be carrying a person: Harry Mudd. He plans to kill Lorca and sell the ship to the Klingons, but when he is caught he blows up the ship instead. Time returns to the party earlier, with Burnham and Tyler called to the bridge again. They are intercepted by Stamets, who is aware that they are in a time loop due to his interactions with the mycelial network. Over several time loops Stamets works with Burnham and Tyler to find a solution to the problem while Mudd gets further in his plan each time. They eventually convince Mudd that he has won, and he ends the time loop. Preparing to receive a boarding party of Klingons, Mudd is instead confronted by his "beloved" Stella and her father, from whom he had stolen her dowry; they take Mudd away. Stamets reveals to Burnham and Tyler that in one of the time loops they had danced together and kissed.
- Stardate 1308.9: Coming to the aid of another Federation ship, the Discovery is unable to prevent its destruction by a Klingon ship with cloaking technology. Desperate for a way to detect these ships even when they are cloaked, Burnham, Tyler, and Saru are sent to Pahvo, a seemingly uninhabited planet with a naturally occurring crystalline transmitter that broadcasts the planet's vibrational frequency into space. They hope to use the transmitter to create a sonar for the hidden Klingon ships. After discovering that Pahvo is inhabited with indigenous, non-corporeal lifeforms that introduce Saru to their higher understanding of peace, Saru attempts to force Burnham and Tyler to remain with him on the planet forever. Burnham is able to fight off Saru and broadcast the new signal. However, the Pahvans adjust the signal to contact the Klingons as well, hoping to end the war. Kol receives the signal, after sentencing L'Rell to death: she had tried to help Cornwell escape in exchange for protection from Kol, leading to L'Rell apparently killing Cornwell to try save face with Kol. Captain Lorca is ordered to flee before the Klingons arrive, but disobeys orders to protect the Pahvans and their own chances of detecting the cloaked ships. When the Klingons arrive, Tyler and Burnham transport to the Sarcophagus ship and plant sensors that will help create an algorithm for detecting the cloaked ships. They find Cornwell alive and hidden with L'Rell, but encountering the Klingon sends Tyler into shock due to PTSD from memories of her torturing and raping him. Lorca has Stamets make 133 micro-jumps in order to provide a three-dimensional reading of the sensors, while Burnham distracts Kol by challenging him to a fight. The jumps are completed, though not without trauma to Stamets. When the algorithm is calculated, Burnham, Tyler, Cornwell, and L'Rell (who wishes to defect) are transported back to the Discovery and the Klingon ship is destroyed. Stamets volunteers to make one more jump to safety, but tells Lorca it will be his last. However, Lorca changes the coordinates and they jump to an unknown destination surrounded by debris from Klingon ships. Discovery's crew determines that they have arrived in a parallel universe, with Stamets now unconscious and unable to power the spore drive. Tyler confronts L'Rell, and she attempts to use a verbal cue to trigger something within him, though he fights it off. From a data core from a wrecked Klingon ship, they learn that this universe is ruled by the Terran Empire, who are fighting a resistance that includes species such as Klingons and Vulcans. Here, Burnham is the former captain of the I.S.S. Shenzhou, presumed dead after an attack by the fugitive Lorca. The I.S.S. Discovery is captained by Sylvia Tilly's counterpart, and she and the crew are forced to pretend to be their Mirror selves. They deliver Burnham and Lorca to the Shenzhou, under the ruse that Burnham had been hunting Lorca since her presumed death and had now captured him. Tyler accompanies them, after first killing Culber when he informs Tyler that he appears to have undergone major surgical modifications and intends to have him removed from duty. On the Shenzhou, Lorca is tortured while Burnham assumes command.
- The I.S.S. Shenzhou is given the coordinates of the resistance leadership, and is ordered to kill them all. Burnham and Tyler travel as a landing party themselves and instead surrender to the resistance in hopes of learning how the Klingons of this universe have learned to work with other species; they find that the Mirror Voq is the leader. Burnham offers to give the group time to escape before their base is destroyed, and Mirror Sarek confirms she can be trusted after connecting to her mind. Listening to Voq triggers Tyler's programming, and he has to be restrained. Back on the ship, he reveals to Burnham that he now knows he was once Voq, and that he underwent surgery to appear human and infiltrate Starfleet. She has him beamed into space, where he is picked up by the U.S.S. Discovery. Saru and Tilly imprison him, having earlier found the body of Culber, and apparently failed to heal Stamets using spores. Burnham is reprimanded for not killing the resistance leaders immediately by the Emperor—the Mirror Georgiou.
- Burnham and Lorca are summoned to the I.S.S. Charon, the imperial flagship. Georgiou sends Lorca to an agony booth, and has dinner with Burnham. Stamets finds himself within the mycelial network with the consciousness of his Mirror counterpart, learning that the network has been corrupted by the Mirror Stamets' experiments. Stamets encounters a representation of Culber and accepts his loss, before waking up to find his spore collection infected. Georgiou laments allowing Lorca to become a father figure for Burnham, only for the pair to fall in love and plot to overthrow her. She plans to execute Burnham, who reveals the truth about being from another universe. Explaining how they had crossed over, Georgiou trades the spore drive's schematics for information on alternative ways to cross between universes, which leads Burnham to realize that the Lorca she knows is actually from the Mirror Universe, and has been manipulating events to get close to her and back to the Mirror Universe. Lorca escapes from the agony booth. Freeing his old crew, who have been tortured since Lorca's disappearance, and with the help of Mirror Stamets, Lorca is able to kill those loyal to Georgiou and usurp her throne. She goes into hiding, while Burnham also evades capture and contacts the Discovery. They agree to a plan in which Burnham lowers the containment field around a large energy source originating from the mycelial network. The Discovery will then arrive to destroy the energy source, causing an explosion which they can ride into the mycelial network, through which Stamets could navigate them home. Georgiou agrees to help Burnham, and they attack Lorca's group. Rejected and defeated by Burnham, Lorca is killed by Georgiou, who offers to sacrifice herself to allow Burnham's escape. The latter instead takes Georgiou with her as they are beamed to the Discovery, and the Charon is destroyed. Back in their own universe, the Discovery crew learns that they have arrived nine months after they left, and in the meantime, the Klingons have nearly won the war.
- The Discovery is boarded by Admiral Cornwell and Sarek, who explain that the Klingon Houses remain divided, and fight between themselves to see which can destroy more Federation assets. The only safe refuge for Starfleet beyond Earth is now Starbase 1, and they warp there with Cornwell assuming command. After emergency surgery performed by L'Rell, Tyler now has his Human personality back, but can still access Voq's memories; Burnham is unable to forgive his actions as Voq. The crew finds Starbase 1 conquered by a Klingon house, and the remainder of Starfleet's command withdraws to protect Earth. Georgiou tells Burnham that she defeated the Klingons in the Mirror Universe with a surprise attack on their homeworld of Qo'noS, and Cornwell agrees to replicate that now. To jump into Klingon territory, Stamets terraforms a desolate moon to grow a new crop of spores so that they can use the spore drive. Georgiou tells Sarek and Cornwell of other essential information she has, and they have her pose as Captain Georgiou to lead the mission. Tyler says that a drone, intended to map Qo'noS and provide possible targets, should enter the dormant volcanic system beneath the surface of the planet through an entrance beneath a shrine. Discovery jumps to a nearby cave, and a party of Georgiou, Burnham, Tilly, and Tyler pose as traders. Tilly discovers that the volcanic system is active, and that the "drone" Georgiou has is a hydro-bomb. Burnham confronts Cornwell, who admits that detonating the bomb in the active volcano will annihilate all life on Qo'noS, winning the war. Burnham insists that Starfleet must not commit genocide, and convinces Georgiou to give up the detonator in exchange for her freedom. They give the detonator to L'Rell, who uses the threat of mass destruction to unite the Klingon houses under her leadership and end the war. The Discovery crew are hailed as heroes, and Burnham is issued a full pardon and restored to the rank of commander. Tyler chooses to remain with L'Rell. As Discovery warps to Vulcan to pick up its new captain, it receives a distress call from the U.S.S. Enterprise NCC-1701.
Notes and References
- Roddenberry, Gene (Executive Producer). "Obsession." Star Trek, Season 2, Episode 18. Directed by Ralph Senensky. Written by Art Wallace. Desilu Productions, 15 December 1967.
- Fuller, Bryan et al (Executive Producers). "Magic to Make the Sanest Man Go Mad". Star Trek: Discovery, season 1, episode 7 (Production number 07). Directed by David M. Barrett. Written by Aron Eli Coleite & Jesse Alexander. CBS Entertainment. 29 October 2017.
- Fuller, Bryan et al (Executive Producers). "Si Vis Pacem, Para Bellum". Star Trek: Discovery, season 1, episode 8 (Production number 08). Directed by John S. Scott. Written by Kirsten Beyer. CBS Entertainment. 5 November 2017.
- Fuller, Bryan et al (Executive Producers). "Into the Forest I Go". Star Trek: Discovery, season 1, episode 9 (Production number 09). Directed by Chris Byrne. Written by Bo Yeon Kim & Erika Lippoldt. CBS Entertainment. 12 November 2017.
- Fuller, Bryan et al (Executive Producers). "Despite Yourself". Star Trek: Discovery, season 1, episode 10 (Production number 10). Directed by Jonathan Frakes. Written by Sean Cochran. CBS Entertainment. 7 January 2018.
- Fuller, Bryan et al (Executive Producers). "The Wolf Inside". Star Trek: Discovery, season 1, episode 11 (Production number 11). Directed by T.J. Scott. Written by Lisa Randolph. CBS Entertainment. 14 January 2018.
- Fuller, Bryan et al (Executive Producers). "Vaulting Ambition". Star Trek: Discovery, season 1, episode 12 (Production number 12). Directed by Hanelle M. Culpepper. Written by Jordon Nardino. CBS Entertainment. 21 January 2018.
- Fuller, Bryan et al (Executive Producers). "What's Past is Prologue". Star Trek: Discovery, season 1, episode 13 (Production number 13). Directed by Olatunde Osunsanmi. Written by Ted Sullivan. CBS Entertainment. 28 January 2018.
- Fuller, Bryan et al (Executive Producers). "The War Without, the War Within". Star Trek: Discovery, season 1, episode 14 (Production number 14). Directed by David Solomon. Written by Lisa Randolph. CBS Entertainment. 4 February 2018.
- Fuller, Bryan et al (Executive Producers). "Will You Take My Hand?". Star Trek: Discovery, season 1, episode 15 (Production number 15). Directed by Akiva Goldsman. Story by Akiva Goldsman & Gretchen J. Berg & Aaron Harberts. Teleplay by Gretchen J. Berg & Aaron Harberts. CBS Entertainment. 11 February 2018.