WARNING: The following contains spoilers for Star Trek: Discovery Season 4, Episode 1, "Kobayashi Maru," streaming now on Paramount+.
Star Trek: Discovery's Season 2 finale catapulted the crew of the USS Discovery 930 years into Starfleet's future to a galaxy where the Federation imploded after a cataclysmically explosive event. Known as the Burn, it caused all vessels using dilithium to power their warp drives, causing them to all simultaneously explode. Discovery Season 3 saw Michael Burnham and her friends discover the origins of the Burn as they grew accustomed to this brave, new world. And for her valor in rebuilding the Federation and Starfleet while discovering a vast store of usable dilithium, Burnham was promoted to captain the Discovery while forming a romantic relationship with 32nd century empath Cleveland "Book" Booker, setting the stage for Season 4.
As the Discovery continues to take point on rebuilding the United Federation of Planets' old alliances, Burnham and Book personally lead a first contact mission to a planet that hasn't been visited by Starfleet since the Burn centuries prior. In a show of goodwill, Burnham offers the diplomatic envoy a supply of dilithium, but this civilization is convinced Starfleet is simply seeking to exploit them for their technology, citing strained relations with the Federation before the Burn. This devolves into a whole misunderstanding when the envoy confuses Book's cat, Grudge, as a prisoner, leading to an epic chase around the planet, culminating in the Discovery restoring the civilization's satellite system while Burnham and Book leave their pursuers the dilithium anyway to help regain their trust.
On the Kelpien world of Kaminar, Saru has been helping Su'Kal acclimate into Kelpien society for months, with Saru revered as a great elder among his own people. While the Kelpiens are unsure about rejoining the Federation and Su'Kal's destructive potential -- as Su'Kal's emotional reaction to his mother's death caused the Burn in the first place -- Saru cites evidence that a similar cataclysmic event to the Burn reoccurring is something of a scientific impossibility. Su'Kal senses that Saru longs to return to the Discovery and his friends but his sense of duty to Kaminar leads him to stay on the planet.
Burnham gets the nod from the new Federation President Laira Rillak to speak at the grand reopening of Starfleet Academy for its rededication ceremony after centuries of closure since the Burn, with Burnham observing that nearly 60 planets are full members of the Federation since the events of Star Trek: Discovery Season 3. Rillak commends the crew of the Discovery for making this all possible before unveiling the Archer Spacedock, a cutting edge facility built to reinvigorate Starfleet's commitment to interstellar exploration and develop means of space travel that move away from dilithium dependency. While Burnham and Tilly finally attempt to catch up between all the hectic missions and Starfleet obligation, Burnham is called away for a new briefing.
Admiral Charles Vance tasks the Discovery with investigating a Starfleet station that went off the grid after sending a distress signal, with Rillak insisting in accompanying the mission on board despite Burnham's vocal misgivings. The Discovery finds the station careening out of control, with Tilly and Adira beaming aboard to lead repairs on the station personally. An anomaly causes a power surge that turns the simple repair job into a rescue mission but the Discovery is unable use its transporters to bring everyone back to the ship. Burnham makes an EVA to steer the station's escape pod back to the Discovery while Rillak talks down the station chief as he panics. While Tilly and Adira are rescued in the nick of time, the station chief is killed by debris when he leaves the station.
Guilty that the mission was not a complete success, resulting in the loss of a life, Burnham is consoled by Rillak who reminds her that leadership is about mitigating loss, not necessarily preventing it entirely -- harkening back to Star Trek's classic no-win scenario, the Kobayashi Maru. As this tense debrief continues, Rillak reveals she feels Burnham is ill-prepared to command a more advanced Starfleet vessel as she is willing to sacrifice too much for too little, which Burnham argues is not a weakness. This discussion is tabled when Book arrives back on the Discovery after his ship mysteriously collided with something before everyone is shocked to discover that Book's home planet, Kwejian, has been devastated by an unseen event.
Created by Bryan Fuller and Alex Kurtzman, Star Trek: Discovery Season 4 releases new episodes Thursdays on Paramount+.