Star Trek: Voyager would have been different in its latter seasons if Kes (Jennifer Lien) had stayed on the USS Voyager instead of departing in Voyager season 4, when her ostensible replacement Seven of Nine (Jeri Ryan) arrives. There’s no narrative reason both Kes and Seven couldn’t have existed concurrently, especially since the differences between Kes’ optimistic innocence and Seven’s detached efficiency could have made for an interesting conflict that would still serve the purpose of invigorating Voyager‘s lagging storylines.

Kes’ early development was bogged down by her relationship with Neelix (Ethan Phillips), but after the pair break up, they’re both free to pursue independent character arcs. While Neelix becomes more interesting, Kes never gets a chance to do the same, despite hints of a potential dark turn for Kes that would have made her a memorable Star Trek:Voyager villain. Kes’ presence in later seasons would also give Captain Kathryn Janeway (Kate Mulgrew) an edge in battling adversarial Delta Quadrant aliens like the Borg, Hirogen, and Species 8472. It’s pure speculation, but consider the possibilities of an alternate timeline where Kes stays on Voyager.

10 The Ocampa Become Important Star Trek Aliens

Star Trek: Voyager‘s premiere, “Caretaker”, makes a grand show of establishing the Ocampa as a new race of Star Trek aliens. Janeway knows that destroying the Caretaker array will strand Voyager on the other side of the galaxy, but she does it to protect the Ocampa, implying they’ll play a major part in Voyager. The Ocampa station in Voyager season 2, episode 10 “Cold Fire” would be the first of many, with each colony’s culture being wildly different thanks to the Ocampa’s short lifespans creating huge generational shifts. Kes could learn something new at each stop, and develop a unifying Ocampa philosophy with the best of each.

9 Star Trek: Prodigy Features Kes’ Descendants

Star Trek: Prodigy is in many ways a sequel to Star Trek: Voyager, with its initial Delta Quadrant setting and incorporation of Voyager characters Admiral Janeway, Captain Chakotay (Robert Beltran), and the Doctor (Robert Picardo). Kes’ nine-year lifespan means she would have passed on by Prodigy season 1 in 2384, but Kes’ wish to be a mother is part of Voyager season 2, episode 4 “Elogium”, and in the alternate future from Voyager season 3, episode 21 “Before and After”, Kes has a daughter. Lien could join the Star Trek: Prodigy cast voicing Kes’ daughter or granddaughter, or new actors could play Kes’ descendants.

8 Kes Champions the Doctor’s Hologram Rights Campaign

Kes’ friendship with the Doctor is one of her first on Star Trek: Voyager, and arguably the best. Through Kes’ compassion and understanding, the Doctor comes to recognize his own humanity, and begins the process of expanding beyond his initial Emergency Medical Hologram programming, with subroutines for hobbies, personality shifts, and deeper emotions. Kes would undoubtedly stand by the Doctor in every step of his evolution, and accelerate the Doctor’s campaign to advocate for hologram rights, which could occur earlier than Voyager season 7.

7 Kes’ Telepathy Makes Species 8472 More Sympathetic

The non-humanoid Species 8472 is the mysterious adversary to the Borg that can’t be assimilated. Kes is responsible for discerning Species 8472’s deadly motives in Voyager‘s season 3 finale “Scorpion”, and able to facilitate telepathic communication with them, but their natural hostility makes negotiation impossible. Kes gains the ability to transcend the limitations of normal matter in Voyager season 4, episode 2 “The Gift”, which would allow her to enter fluidic space and meet Species 8472 on their own terms. Doing so might make them more receptive to communication and lead to an eventual peace between Species 8472 and the Federation.

6 The Hirogen Make Kes a Primary Target

Star Trek: Voyager season 4, episodes 18 & 19 “The Killing Game” sees the predatory Hirogen using Voyager’s own holodeck technology to turn the Voyager crew into unwitting prey with no memory of their true identities. In the original episode, the Doctor reconfigures Seven’s Borg implants to jam the Hirogen neural interface responsible for the memory wipe; in this version, Kes’ Ocampa powers could let her know something isn’t right, which would prompt investigation. The ability to see through the Hirogen ruse would paint a target on Kes’ back, leading to the Hirogen pursuing Kes specifically.

5 Neelix Admits His Relationship with Kes Was Creepy

Kes’ actual return to Star Trek: Voyager comes in Voyager season 6, episode 23 “Fury”, in which an older Kes wrongly blames Janeway for taking advantage of young Kes not knowing better. Similarly, an older and wiser Kes might realize that her earlier relationship with Neelix really was a situation in which Kes was taken advantage of due to her inexperience. A conversation between Kes and Neelix addressing how messed up their romantic relationship was would help him understand Neelix took advantage of their power imbalance, and possibly even apologize for it.

4 Kes Grows Old & Dies Before Reaching the Alpha Quadrant

When Star Trek: Voyager started, Kes being a member of a species that only lives nine years created an interesting conundrum. If Voyager were to run for seven years, like Star Trek: The Next Generation had, the two-year-old Kes would grow into old age and die before the end of Voyager. “Cold Fire” introduces Ocampa who live to be past 15 years old, so a narrative failsafe existed, but the concept of Kes’ whole life being lived over the run of Voyager is a fascinating promise that could be fulfilled if Kes remains on Voyager. It’s made more heartbreaking if Kes dies before Voyager reaches the Alpha Quadrant.

3 Kes Helps Janeway Defeat the Borg With Psychokinetic Power

In Star Trek: Voyager season 4, episode 2 “The Gift”, Kes is able to perform delicate surgery to psychokinetically remove Seven of Nine’s more integrated Borg implants. In this case it’s a benefit that lets Seven become more human, but this type of fine control could also be used offensively, to disable Borg drones at a distance. As Kes’ Ocampa power grows stronger, she could find herself capable of shutting down an entire Borg Cube, and possibly even the Borg Queen (Susanna Thompson, Alice Krige). Captain Janeway would have few qualms about using Kes as a weapon if it means saving the galaxy from the Borg permanently.

2 The Dark Side of Ocampa Power Makes Kes a Voyager Villain

Star Trek: Voyager season 2, episode 10 “Cold Fire” shows Kes’ telepathic power growing stronger when she gives in to her baser emotions, and Voyager season 3, episode 10 “Warlord” shows Lien’s skill at playing evil. The hints at a dark side to Kes could have been explored in a genuinely interesting character arc of Kes’ descent into selfish villainy, and eventual rise as a stronger and more balanced individual. Kes’ theoretical redemption arc would dovetail nicely with Seven’s existing one, as both characters embody the push and pull between selflessness and individuality.

1 Kes Staying on Voyager Affects Seven of Nine

Kes’ ability to see the best in others early on brought out the Doctor’s humanity, so it’s reasonable to think that Kes would try to play the same role for Seven of Nine, after Seven is liberated from the Borg Collective and grappling with her own humanity. Seven is unlikely to be as receptive to Kes’ attempted friendship, especially if Kes is responsible for dismantling other Borg drones who were still firmly entrenched in the Collective. Seven has a tendency to point out contradictions in others’ behavior, so she’d call Kes out on the hypocrisy of respecting all life while essentially murdering an entire cube of drones with a single thought.

Seven of Nine and Kes would likely have a fraught relationship, owing to the differences in their individual philosophies, but Kes’ potential turn after giving in to darker tendencies would also give Seven an opportunity to see a Starfleet-style redemption story from the outside, with a reflection that could accelerate Seven’s own acceptance of herself. If Kes doesn’t go dark, Kes would affect Seven’s development with an insistent friendship that’s gentler than Neelix’s abrasive joy, more insightful than the Doctor’s studied advice, and more patient than Janeway’s stubborn guidance.

The exact reason for Lien’s departure from Voyager remains a mystery, with an original explanation that Kes was a difficult character to write for with few story prospects, and more recent reports suggesting writing Kes off Voyager was in service of Lien’s struggles with mental health. Perhaps in an alternate timeline, a different version of Star Trek: Voyager exists where Kes stays aboard until her death, but in this universe, all we can do is speculate on what that might be like.