Stark Trek: Discovery takes place about a decade before Star Trek: The Original Series and follows Michael Burnham and the crew of the USS Discovery during a war between the Federation and the Klingons.
Michael Burnham is the First Officer of the USS Shenzhou and is Spock’s foster sister, as Spock’s parents Sarek and Amanda took her in and raised her on planet Vulcan after she was orphaned at a young age.
At the beginning of the season, we see the beginnings of the cold war between between the Klingons and the Federation. The war started when Michael Burnham found an ancient vessel during an investigation of a damaged satellite and is attacked by a Klingon soldier. Michael accidentally kills the soldier, which provokes Klingon leader T’Kuvma, to bring together the Klingon houses against the Federation.
To try and avoid a war against the Klingons, Michael directly disobeys Captain Philippa Georgiou by firing on the Klingons. She fails which means that T’Kuvma kills Captain Georgiou.. Because of this Burnham is arrested for mutiny and stripped of rank. Burnham then kills T’Kuvma and is sentenced to life in prison for her mutiny.
After six months, Burnham is being transferred from prison when her shuttle has an emergency and is rescued by the USS Discovery helmed by Captain Gabriel Lorca. Lorca asks Burnham to work for him, explaining that he organized the circumstances that led her to him so she could help develop a new spore-based propulsion system that could win the war she started by killing T’Kuvma.
We then see the war with the Klingons coming to a conclusion and Lieutenant Paul Stamets makes a jump to safety. This sees the USS Discovery arrive in unchartered territory: a parallel universe named the Mirrorverse, which is run by a cutthroat, repressive government that rules by terror. Burnham finds out that Captain Lorca of the Discovery is actually from the Mirror Universe and has purposely been trying to get back to it.
Michael’s love interest Ash Tyler was actually their Klingon enemy Voq, remade to look just like Ash, but with Ash’s memories implanted and Voq’s memories hidden. In the end, Tyler’s personality remained but had Voq’s memories.
At the end of Season 1, the Discovery received a Priority 1 distress call from the USS Enterprise, with Captain Pike on board. Burnham gets her mutiny charge expunged and is officially named a Starfleet commander. Tilly enters the command training program, and Saru becomes the first Kelpien to receive Starfleet’s medal of honor.
STAR TREK: DISCOVERY: SEASON TWO, out NOW on Blu-ray™ and DVD from CBS Home Entertainment and Paramount Home Entertainment.