Endgame is the title of the series finale of the Star Trek spinoff series, Star Trek: Voyager.
In the year 2404, Earth is celebrating Voyager's tenth anniversary of its 23 year journey home. However, an elderly Admiral Kathryn Janeway plans to go back in time to bring Voyager and her crew home, via a Borg “transwarp corridor,” saving the ship sixteen more years of being stranded in the Delta Quadrant and in the process saving the lives of several crew members, including Seven of Nine, who would die on a future away mission.
The elder Admiral Janeway brings back advanced technologies that would give the USS Voyager the opportunity to get past the massive Borg defenses and enter the corridor. On encountering the Borg, the technology is used to grand effect, destroying two Borg Cubes and giving the ship a clear path to return home.
However, the admiral’s efforts are hindered by the desire of her younger self to use the future technology to cripple the Borg instead of using it to return home. The two Janeways argue over the issue until the elder Janeway tells her younger self that Seven of Nine will die if they do not take the road home. Though Captain Janeway is moved by this confession, she decides that the foreknowledge of Seven's death means it is no longer certain. The Admiral mentions that, while that might be the case, Tuvok has no chance, already suffering from a degenerative condition and it will get worse if they don't get home. After discussing the issue with the rest of her crew, Captain Janeway decides to go ahead with her plan to destroy the Borg’s transwarp hub, their center for transport around the galaxy. On seeing the crew’s selfless reaction to the plan, the older Janeway rediscovers a piece of her old fighting spirit and with Captain Janeway, comes up with a plan to both destroy the hub and possibly get Voyager home.
Admiral Janeway takes her shuttlecraft and enters one of the transwarp hubs, taking her to the Unicomplex—the center of all Borg activity, where the Borg Queen herself resides. Tricking the queen into “assimilating” her into the Borg collective, Admiral Janeway unleashes a pathogen that devastates the Borg, destroying the queen, the Unicomplex and the transwarp hub.
Meanwhile Captain Janeway and her crew have entered a transwarp corridor and are traveling back to Earth, pursued by a Borg sphere ship that has withstood the pathogen’s effects. Unable to fight back against the ship’s exterior defenses, Janeway takes her ship inside the sphere, where, upon its arrival in the Solar System, she detonates a torpedo that destroys the sphere from the inside out.
In the show’s final few minutes, the crew stand dumbfounded that they have finally returned home after seven years lost in the Delta Quadrant. Settling down in her chair, Captain Janeway issues her final words; the same words that she used at the start of her journey: "Set a course...for home."
The final episode also includes the birth of Miral, daughter of Tom Paris and B’Elanna Torres. Miral is born as Voyager reenters Earth’s solar system. The sounds of the baby’s gurgling are heard over the communications system, to the joy of all the crew. In the future, she is an ensign on a classified mission to negotiate getting a chrono deflector.
Commander Chakotay and Seven of Nine are revealed to have started dating. Though Seven is at first wary of the relationship, and more so after Janeway tells her of her own death, Chakotay persuades her that he wants to be with her, even if it's uncertain how long they will be together; however Janeway's older self suggests that Seven and Chakotay will eventually be married. In the future, Seven died on the trip home and it is implied that Chakotay couldn't handle the trauma. He was buried on Earth 33 years later.
Tuvok is suffering from a degenerative brain disease, yet does not tell the Captain as the only cure is a mind-meld with a family member—logically, he does not want to distract the Captain. In Admiral Janeway’s future, the disease is too advanced to be cured and he is in a mental institution.
The Doctor’s “name” saga is finally concluded in the first few minutes of the show, where a future Doctor is seen confessing that he has finally decided to call himself Joe, taking thirty-three years to come up with that name, after his new wife’s grandfather. This revelation takes place in an alternate future, one in which the Voyager crew does not ultimately end up.
Neelix makes a brief appearance on the communications screen talking to Seven of Nine. Two episodes previously he had left to join a Talaxian colony. His first appearance in the show was also on a viewscreen.
Harry Kim is the captain of the U.S.S. Rhode Island. He goes to stop Admiral Janeway from going back in time, but he ultimately decides to help his old friend in her cause. Ironically, in another timeline, it was Harry in the Voyager episode "Timeless" who was determined to rewrite the past and prevent a disaster.
In the last few scenes of this episode, six classes of Starfleet ships, arguably the most popular of the TNG era, are seen: Defiant, Galaxy, Excelsior, Nebula, Prometheus and Intrepid (Voyager itself).
The shooting adventure game Elite Force II uses an 'unseen' part of the series finale as a plot device. In the first level of the game, Voyager's Hazard Team is assigned to beam aboard the Borg Sphere which has trapped Voyager inside during the trans-warp pursuit, in order to disable the dampening field which, it is claimed at the start of the level, is keeping Voyager captive. The level overall represents the length of 'real time' that Voyager is trapped within the sphere before it ultimately blasts its way out. The level's end is ultimately followed by a cutscene immitating the very end of the 'Endgame' episode, using the game engine's CGI, before it cuts as a segue into the office of a Starfleet administrator on Earth, where the game then continues. The game's plot also states that Tuvok is temporarily assigned as Tactical Officer and First Officer of the USS Enterprise E, following Voyager's return to Earth and William Riker's re-assignment to the starship Titan.