Jack Crusher (played by Ed Speleers) had the potential to become the Borg King in season 3 of Star Trek: Picard if his father, Admiral Jean-Luc Picard (portrayed by Patrick Stewart), hadn't intervened to save him. The thrilling conclusion of Star Trek: Picard season 3 saw Picard leading the USS Enterprise-D into hiding within a Borg Cube located in Jupiter. Jean-Luc managed to rescue Jack, who had been assimilated by the Borg Queen (played by Alice Krige) and transformed into Vox of Borg, just before the Enterprise destroyed the Cube. This marked the end of the threat posed by the United Federation of Planets' most formidable enemies.
The son of Jean-Luc Picard and Dr. Beverly Crusher (portrayed by Gates McFadden), Jack Crusher is a child with a cosmic destiny. However, he was unaware that his destiny involved becoming Vox of Borg. From a young age, Jack experienced disturbing visions and heard voices. Eventually, Beverly determined that her son had inherited organic Borg DNA from Jean-Luc during his time as Locutus of Borg. Jack confronted the Borg Queen and ended up being assimilated. As Vox, Jack's purpose was to amplify the Borg's signal, assisting them in their evolution by assimilating every Starfleet Officer below the age of 25 to form a new, evolved Borg Collective. With the Borg's defeat and Dr. Crusher's advancements in medical technology, Starfleet's youth was restored, and Jack was given a new opportunity to follow in his parents' footsteps as a Starfleet Officer serving on the USS Enterprise-G.
How Jack Crusher Could Have Been Star Trek's Borg King
If Star Trek: Picard season 3 hadn't concluded with Jean-Luc saving his son and Starfleet achieving victory against the Borg, there was a possibility that Jack Crusher could have emerged as Star Trek's first Borg King. Despite the Borg Queen's desire to retain control over the Collective, it was evident that she was nearing her end. Two decades earlier, the Borg had suffered severe damage from a neurolytic pathogen administered by Admiral Kathryn Janeway in Star Trek: Voyager's finale. The Queen resorted to feeding on her own drones to survive, but she was weakened and barely holding on when she transformed Jack Crusher into Vox.
Although Jack became lost within the Borg Collective's "perfect order," being a Picard and a Crusher, there existed the potential for Vox to assert his individuality within the Collective. Vox could have grown strong enough to challenge the dying Borg Queen and take her place as the first Borg King. With control over the assimilated Starfleet Borg as the amplifier, Vox would have immense power over this newly evolved Collective. As Vox, Jack could have replaced the Borg Queen and her remaining drones with his own version of the Borg. However, due to the intervention of Jean-Luc Picard, the Enterprise, and their actions, this scenario will remain unrealized, and the galaxy will be spared the threat of Jack Crusher imposing his "perfect order" as the Borg King.
Star Trek Won't Do Jack Crusher's Borg Vs. Agnes Jurati's Borg
Star Trek: Picard season 3 concluded by setting up the potential spinoff, Star Trek: Legacy, and establishing Jack Crusher's role. The newly-enlisted Ensign Crusher became Captain Seven of Nine's "Special Counselor," while Q returned and hinted at his significance in the future of the galaxy, much like his father, Jean-Luc Picard. It is probable that Jack's future does not involve the Borg or ruling over them, indicating that Star Trek: Picard has put an end to the Borg as the primary antagonists from Star Trek: The Next Generation.
On the other hand, the conclusion of Star Trek: Picard season 2 introduced a benevolent faction of the Borg in an alternate reality, led by a combination of the Borg Queen and Dr. Agnes Jurati, who are now allied with the Federation. Nevertheless, Star Trek: Legacy will not center around a conflict between the Jurati Borg and the evolved Borg led by Jack Crusher. Although this could have been an exciting storyline for a post-Star Trek: Picard narrative, it is ultimately more beneficial for the future of the galaxy if Jack Crusher never becomes the first Borg King.