Seska was a 24th century Cardassian operative, surgically altered to appear Bajoran in order to infiltrate the Maquis. Before being stranded in the Delta Quadrant with the rest of her Maquis team and the USS Voyager crew, she was assigned to Chakotay's Maquis raider, the Val Jean and used her relationship with him to steal Maquis secrets.
The Maquis and USS Voyager
She served under Chakotay aboard the Maquis raider Val Jean when it was catapulted into the Delta Quadrant by the Caretaker's array in 2371. (VOY: "Caretaker") She was close friends with B'Elanna Torres and on the ship was granted the field commission of ensign, initially in the science department but later moving to engineering. Not very fond of the Federation, Starfleet, and their "mighty principles", she often expressed her disapproval and annoyance with their rules and made it clear to Chakotay that if the situation ever necessitated it, she would support a Maquis mutiny. (VOY: "Caretaker", "Parallax", "Prime Factors")
She was involved with Lieutenants Torres, Joe Carey, and Tuvok in a covert attempts to acquire spatial trajector technology from the Sikarians, behind Captain Janeway's back. When their plan to steal the technology failed, she attempted a cover-up , but Torres held her back, stating that she did not want to lie anymore – something Seska found rather disappointing. (VOY: "Caretaker", "Parallax", "Emanations", "Prime Factors")
Her disdain of Starfleet and Starfleet principles, such as the prime directive, lead to her distancing herself from the crew further, ultimately leading to collaboration with the Kazon-Nistrim, offering them replicator technology in exchange for their help in this unknown part of the galaxy. She did not care that something simple like replicators could shift the balance of power in this part of the quadrant as her primary goal was to get back home. (VOY: "State of Flux").
Her true origins remained undiscovered until the time she helped transfer replicator technology to the Nistrim and was seriously injured during the transfer. The Doctor's subsequent examination caused her true Cardassian nature to be revealed. She denied this fact, claiming that she had suffered from Orkett's disease as a child and received an extensive transfusion from a Cardassian to survive. When Chakotay confronted her, revealing the cover-up, she finally confessed to everything and openly expressed her dislike for Captain Janeway's decision, calling her a fool for having gotten them stranded in the Delta Quadrant and unwilling to give the Kazon what they wanted so Voyager had an ally. She also expressed her disappointment in Chakotay, whom she believed had naively followed Janeway's footsteps, and stated that she couldn't imagine why she had ever loved him. Before she could be further questioned, she managed to escape Voyager and transferred aboard a Kazon raider. (VOY: "State of Flux")
Collaboration with the Kazon
After Seska left Voyager, she immediately restored her Cardassian physiology and became the consort of First Maje Culluh, the leader of the Kazon-Nistrim sect. Culluh had a thirst for power and she used that to manipulate him to do what she wanted. Equipped with Starfleet, Maquis, and Cardassian tactical experience, she provided the Nistrim with expertise on Voyager and schemed ever newer ways of stealing the ship and its technology.
In order to capture Chakotay, she planned a successful attempt to steal a transporter control module from Voyager, knowing that he would come after it. Even though Chakotay was able to destroy the module, he was captured and heavily beaten during interrogation. During his capture, Seska tried to get close to Chakotay but he rejected her advances, later laughing at Cullah, telling him that when Seska was through with him, she would kill him.
Shortly after Chakotay was rescued, Seska contacted him, claiming that she had impregnated herself by extracting his DNA and that she was carrying his child. At the same time, she had also told Culluh that the child belonged to him, thus using the baby to manipulate both men. (VOY: "Maneuvers")
Later that year, she and Cullah were contacted by Janeway and her crew who proposed building an alliance with the Nistrim in exchange for providing them with emergency supplies where needed. Culluh - who did not want a woman to dictate the terms of the agreement - insisted on a crew exchange as condition of the alliance; a proposal Janeway found unacceptable, resulting in the end of further negotiations. When Voyager formed an alliance with the Trabe - an enemy of the Kazon - instead, Seska was angered, accusing Culluh of having let Voyager slip away because of his attitude, which she promised would one day be his undoing. Even though Cullah did not like being talked to like that by a woman, she always managed to manipulate him to look the other way and acquiesce to her demands and scheming. (VOY: "Alliances")
Seska was not the only one disillusioned with Captain Janeway's policies: Voyager crewmember Michael Jonas also appeared to harbor resentment towards the Starfleet policies he had to live by and soon after Seska left, he contacted her, offering to collaborate with her and help sabotage the ship by supplying her and the Nistrim with vital information pertaining to Voyager. However, Janeway and Tuvok discovered Jonas's transmissions and through an elaborate plan were able to expose him. (VOY: "Investigations")
In late 2372, Seska gave birth to the child she claimed to be Chakotay's. She immediately contacted him, claiming that Culluh had discovered that the child was not his and threatened to have the child be raised as a slave. This lured Voyager into a trap in which a Kazon operative named Tierna was able to enter the ship and detonate organic explosives in his bloodstream while on board, disabling the ship's power systems and the primary computer core. Janeway was unable to activate the auto-destruct sequence in time and the ship was boarded by Kazon troops. Soon after Seska and Culluh took over the ship, they marooned its crew on a desolate planet named Hanon IV.
During the Kazon occupation of the ship, Seska took stringent precautions against any possible threats, even questioning The Doctor's loyalty. That line of questioning was cut short when he revealed through a DNA analysis that her baby was actually half-Kazon, not Human, and thus not Chakotay's. This greatly disappointed Seska, who had been sure that the baby was half-Human and was hoping to forever trap Chakotay by her side.
After taking over the ship, Seska and Culluh did not get very far, however, as most of the Kazon were ill-equipped to navigate and control the ship's complex and unfamiliar technology. In addition, Tom Paris - who had left Voyager in a shuttle prior to the Kazon attack to seek help - with assistance from Talaxian forces, as well as The Doctor and Lon Suder, was able to retake the ship. During the mission to recapture Voyager, Seska was mortally wounded in the resulting overload of the console she was at and only had a few minutes to live before she collapsed with her baby in her arms. Culluh discovered her body and escaped with their son just before the crew returned. (VOY: "Basics, Part I", "Basics, Part II")
At some point in the early days of Voyager's journey through the Delta Quadrant, Tuvok had created a holodeck training simulation program called "Insurrection Alpha" depicting a Maquis mutiny. At the beginning of their journey he had perceived such a rebellion to be very real threat and had devised a program to train Starfleet personnel in case of such a contingency. However, when he realized that the two crews were getting along better than anticipated, he deleted the program and never told anyone about it, fearing that it would trigger the very mutiny he wanted to avoid. At some point, Seska had discovered it and secretly reprogrammed it to act as a trap. In 2373, the program was discovered by Torres and played several dozen times by various crewmembers, who found the story line very intriguing. When Tuvok and Tom Paris attempted to alter the program by writing an ending for it, Seska's trap was triggered and both men became trapped in the holoprogram with the safety protocols off. However, Captain Janeway was able to reprogram portions of the simulation to allow Tuvok and Paris to escape, simultaneously causing the "death" of the holographic Seska. (VOY: "Worst Case Scenario")
In 2377, a temporal distortion shifted sections of Voyager into different timeframes with Chakotay being the only one capable of traveling between timeframes unaffected by the temporal distortion. One of the areas he visited was engineering during the Kazon-Nistrim takeover of the ship in 2372. There, he encountered Seska and a number of Kazon trying to gain control of the ship. Although he was forced to tell Seska the truth about what had happened, when Seska learned that the Kazon were defeated in their efforts, she attempted to stop Chakotay's efforts to restore the timeframe, holding a past version of Janeway hostage to try and make him modify the plan to return Voyager to her time. However, these plans failed thanks to the intervention of various allies Janeway and Chakotay had recruited from other time periods – such as future versions of Icheb and Naomi Wildman or a still-Borg Seven of Nine – and Voyager was successfully restored to its original configuration in the correct timeline. (VOY: "Shattered")
Seska and Chakotay were romantically involved sometime in the past, although they had eventually decided not to pursue their relationship any further. However, a certain attraction between the two still existed and when Chakotay once reminded Seska of their decision to not be together anymore, she laughed it off, joking that stranded in the Delta Quadrant, he didn't have all that many options. Despite being hesitant to pursue a romantic relationship with her, Chakotay nonetheless had a soft spot for Seska and when she was accused of sabotage and collaboration with the enemy, he was the only one taking her side until the truth about her betrayal came out. Chakotay was devastated to find that not only had she collaborated with the Kazon but that in fact she was a Cardassian spy. Even though she insisted that she had truly loved him and was not after his meager Maquis secret, he still felt betrayed. Shortly after she was exposed and before her departure from Voyager, she expressed her deep disappointment in Chakotay who had decided to take on the kind of "mighty Starfleet principles" she abhorred and believed to be a hindrance to their efforts to find a way back home. She wondered how she could ever have loved him and shortly after beamed off the ship. (VOY: "State of Flux")
After this betrayal by Seska, Chakotay felt a great sense of shame and disappointment, because she had not only taken advantage of his trust but also because after everything he had done for her, she publicly humiliated him by turning out to have been a Cardassian spy who now had, once again, turned her back on him by defecting to the enemy.
Seska's infatuation and obsession with Chakotay did not end after her departure and she resorted to any manipulation possible to bring him to her, such as the time she lured him into a trap in which he was caught and tortured by Cullah and his men unsuccessfully for information about Voyager. She also used that opportunity to impregnate herself by extracting Chakotay's DNA. After the baby was born, she once again lured him to her side by pretending that the child was in harm. Unable to abandon his child, Chakotay – as soon as he found out – pursued her; a pursuit that lead to the capture of the Voyager by the Nistrim and to the crew being marooned on Hanon IV. (VOY: "Maneuvers", "Basics, Part I", "Basics, Part II")
When Seska had found Tuvok's Insurrection Alpha holonovel training program depicting a Maquis mutiny and reprogrammed it with the goal of trapping whoever played it into the program, she had programmed the novel to portray a holographic Chakotay to be strongly enamored by her, and the two were enthusiastically living out their old wild Maquis ways the way Seska had always pictured and dreamed it would be. (VOY: " Worst Case Scenario")
B'Elanna Torres and Seska were somewhat kindred spirits not too unfamiliar with the strong emotions that come with anger. Both had also served in the Maquis under Chakotay's command and up until Seska's betrayal, they were good friends. At some point it even looked like Seska was warming up to the Starfleet crew, such as the time she and B'Elanna were joking with and teasing young Harry Kim about his disastrous date with one of the Delaney sisters on the holodeck. However, unlike Torres who did make efforts to integrate into the crew, Seska rejected all that and chose a life more in tune with her Cardassian background. Torres pursued the spatial trajector technology of the Sikarians after Seska manipulated her to feel sorry for her now that she could not see her brother on his birthday as promised. When their plan backfired, Seska wanted to cover everything up by deleting all evidence leading to them. However, Torres held her back, saying that she was no longer going to lie and instead would take responsibility for her actions; a move that left Seska disappointed in Torres, accusing her of "having changed." Torres viewed the change Seska mentioned as a compliment and even though she did feel betrayed after the truth about Seska came out, unlike Chakotay - she was able to put it behind her. (VOY: "Prime Factors", "Maneuvers").
- Seska was played by actress Martha Hackett.
- Although Seska was invariably referred to as "ensign" during her appearances in uniform, she wore what otherwise figures to be the provisional rank insignia of an enlisted crewman (one hollow stripe).
- In 2002, Seska placed eighteenth in TV Zone's list of the top twenty science fiction television villains. The Borg Queen was second, Dukat was fourth, Weyoun was eighth, and Q was eleventh.
- Seska's true intentions in helping the Kazon-Nistrim were never explicitly revealed, though she initially claimed that by helping them, she would be helping Voyager gain a protective ally. (VOY: "State of Flux")
In the Voyager novella "The Third Artifact", part of The Brave and the Bold, Book Two, Seska's past as an undercover agent for the Cardassian Empire is explored. In there, Seska had been made an intelligence operative for the Obsidian Order in 2361 and by 2367 she underwent surgical operations to transform her Cardassian physiology into that of a Bajoran so she could infiltrate the Bajoran Resistance. After the Occupation of Bajor ended in 2369, Seska was assigned to spy on the Maquis.