This current Golden Age of Star Trek television will see five concurrent shows on the air by the end of 2022. It all started with Star Trek: Discovery, a prequel series to the original Trek show, set ten years before the voyages of the starship Enterprise under Captain James T. Kirk.
Discovery’s latest finale concludes a fourth season that found a winning balance between examining a galaxy-spanning mystery and exploring how its characters continue to adjust to their new lives. They have come nearly a millennium into the future, into a galaxy where the United Federation of Planets has been fragmented and warp drive is dangerous. Season 3 followed Michael Burnham (Sonequa Martin-Green) as she and the Discovery crew navigated this new reality.
After reconnecting with what remains of Starfleet, the Discovery quickly becomes critical to re-establishing the now-decimated Federation. After most of the galaxy’s dilithium became unstable and erupted a couple centuries prior to Discovery’s arrival, faster than light travel became impossible. With its mycelial spore drive, Discovery becomes instrumental in discovering the origin of the so-called Burn and knitting the intergalactic community back together.
The Dark Matter Anomaly
After welcoming a highly skeptical species back into the Federation with Burnham, Cleveland "Book" Booker (David Ajala) returns to his homeworld of Kwejian for his nephew's coming-of-age ceremony. He leaves just in time to survive the planet's destruction. Discovery's resident scientific genius Commander Paul Stamets (Anthony Rapp) determines that Kwejian's destruction was caused by an unknown and never-before-seen gravitational distortion sweeping through the sector. Captain Saru (Doug Jones), rejoins Discovery to serve as Burnham's first officer, and the ship investigates the phenomenon.
After a close call when what comes to be known as the Dark Matter Anomaly (or DMA, for the convenience of the show's writers) suddenly changes course, the Discovery crew works to hold the still-fragile Federation together. After the DMA inexplicably vanishes and then reappears about 1,000 light-years away, the Federation determines that only an extraordinarily advanced life form could have the technology to create and control such a thing. After investigating a subspace rift left behind in the DMA's wake, Discovery determines that where it goes, it leaves a toxic void drifting through space behind it.
As a highly sensitive empath, Book struggles with his anger and grief. When the roguish Risan scientist Ruon Tarka (Shawn Doyle) joins Discovery to study the DMA, Book finds a kindred spirit. Tarka develops a model of the DMA's power source in the hopes of finding a way to stop the anomaly. Meanwhile, Discovery's sentient computer, named Zora (a system that evolved from the "sphere data," information the crew retrieved from an ancient, advanced creature and went forward in time to keep out of the wrong hands), determines where the DMA must have originated. She refuses to share the information on what they call Species 10-C out of her fear for the crew's safety.
The crew eventually determines that the DMA is actually a massive harvester, and it is in fact mining a rare element known as boronite. They deduce that the boronite is being used to power something designed to shield the 10-C from communications and scans.
Crossing the Rubicon
As Stamets and the Discovery crew struggle to get through to Zora, Burnham and Book attend an emergency council made up a Federation and non-Federation representatives. A debate ensues on whether to immediately attempt to destroy the DMA or attempt first contact with Species 10-C first, lest such an advanced race retaliate with something worse. Book and Burnham find themselves on opposite sides of the argument. The key to either decision is the location of this unknown species, which Zora will not reveal.
On Discovery, another parallel debate finds the ever-mysterious operative Dr. Kovich (David Cronenberg) arguing that since Starfleet has regulations against allowing a self-aware AI to remain in control of a starship, Zora's reasoning is not valid. However, the Discovery personnel convinces Kovich that since Zora is a product of the sphere data evolving as it interacted with the ship's crew, she is actually a completely new life-form. As a sentient being, Zora has the right to choose her own path, but must become a member of Starfleet. Zora agrees, and reveals the coordinates of where she has determined Species 10-C must be: outside the galactic barrier.
Burnham convinces the council to choose a peaceful first contact. This puts her in direct conflict with Book, with whom she is romantically involved. Tarka and Book leave in Book's ship, intent on destroying the DMA's power source with a weapon Tarka has designed. The last half of the season becomes a race against time: Burnham and Discovery must track Book and Tarka down before they can complete the weapon while they figure out how to they'll find and try to communicate with the 10-C.
Beyond the Barrier
Book learns more about the brilliant Tarka, who wants to prevent more destruction, but acts out of a place of grief similar to Book. Tarka was a prisoner of the Emerald Chain, the enslaving warmonger collective Discovery managed to disrupt during Season 3. He befriended and eventually fell in love with Oras, an equally brilliant scientist who had designed an interdimensional transporter. Tarka wants to use the DMA's power source to try and reunite with Oras. Book is concerned that Tarka is less than trustworthy, but continues to work with him. They manage to fool Zora's sensors and attach themselves to Discovery's hull as they pass through the galactic barrier.
Burnham and Discovery go where no one in the franchise has gone before, and explore the space beyond the Milky Way. Several representatives of the Federation join Discovery for the journey, (with no guarantee that anyone will return), including the Federation President, Laira Rillak (Chelah Horsdal), who shares human, Bajoran, and Cardassian ancestry, T'Rina, (Tara Rosling), the leader of N'Var (which was once called Vulcan, but changed its name after reunification with the Romulans), and General Ndoye of United Earth (Phumzile Sitole). Ndoye was a holdout among the members of the emergency assembly, and voted to preemptively destroy the DMA's power source rather than engage in peaceful first contact. Book and Tarka — attached to Discovery and thus far undetected — manage to convince Ndoye to help them when the time is right. Unbeknownst to Book, Commander Jett Reno (Tig Notaro) discovers Tarka, who takes her hostage.
Discovery finds a dead planet in the star system adjacent to a massive hyperfield which squelches all attempts to scan beyond it. Surmising that the planet may be Species 10-C's homeworld, Burnham and the crew race against time, having learned that the DMA is now on a path which will destroy N'Var and Earth. The crew learns that 10-C appears to communicate via the use of complex compounds of hydrocarbons to express emotional states. The crew is able to develop a possible "bridge language" involving mathematical equations in order to begin communicating.
"But to Connect..."
Meanwhile, Reno spies Tarka's calculations, and sees that when Tarka removes the DMA's power source, it will leave behind a toxic void just as dangerous as the DMA itself. Book finally turns on Tarka, who imprisons him with Reno. Tarka goes rogue, attacking the DMA's power source just as Burnham and the high-level representatives gain real ground in communicating with the 10-C. This species did not realize higher forms of life existed in the DMA's path. They express sadness and regret, but Tarka's attack derails everything.
The Discovery crew manages to reestablish communications with the 10-C, who do not understand that Tarka is a separate entity from the others. The 10-C's minds are all linked, with no understanding of the concept of individuality. General Ndoye, who helped put Book's plan into motion, rams Book's ship with a shuttlecraft as a way to atone. She is transported back aboard Discovery with Reno, but Book apparently dies in the explosion along with Tarka. The 10-C sees what has happened and reintegrates Book's transporter pattern, and he materializes on the Discovery bridge.
With his empathic (near-telepathic?) powers, Book is able to share his grief with the 10-C collective. He convinces them that they must disable the DMA altogether, and allow themselves to reconnect with the larger universe. He succeeds, and the ship and crew return to their own galaxy. Discovery is greeted by the President of United Earth (future U.S. president Georgia gubernatorial candidate Stacey Abrams in a fun cameo) and learns that Earth will finally rejoin the Federation. Book will work with the societies that have been hurt by the DMA as a punishment for his crimes, and leaves Burnham.
Like the end of Season 3, the Season 4 finale of Star Trek: Discovery caps a self-contained and satisfying season. So far, Discovery has successfully abandoned the season finale cliffhanger model with any apparent loss of viewership between seasons. It will be interesting to see if this continues into Season 5, what with the highly serialized nature of streaming narratives.