Before Enterprise

In Season 3, episode 24 "Zero Hour", while talking with Trip on February 14, 2154,^[8] T'Pol states that she "will only be 66 years old" on her next birthday. This places her birth in 2088 or 2089 (as measured on Earth), making her 62 or 63 years old at "Broken Bow".^[9] T'Pol was born the only child of T'Les, an instructor at the Vulcan Science Academy, and her (never named) husband. Per Vulcan tradition, T'Pol was bonded with a Vulcan named Koss while they were children and expected to marry as adults ("Breaking the Ice").

As a child, T'Pol's path in life was inspired by Ambassador V'Lar whom she watched negotiating with the Andorians during the Treaty of 2097 over possession of the planetoid Paan Mokar ("Fallen Hero").

Approximately 16 years before joining the crew of the Enterprise, T'Pol served as an agent for the Vulcan intelligence service. At age 47, she completed her training for the Vulcan Ministry of Security. During an early mission to apprehend a pair of Vulcan criminals, she was forced to shoot and kill one of the fleeing men. She resigned from the service as a result, and the guilt over killing someone face-to-face caused her to suffer a nervous breakdown or emotional collapse which led to her undergoing a procedure, the Fullara, that erased all memory of the incident. This "memory cap" disappeared when she was briefly reactivated as an agent during 2152 in order to capture the criminal Vulcan who eluded her that day, and she experienced another emotional collapse which was alleviated by the support of Captain Archer. Given the option to once again suppress her memory of killing, she chose to live with it instead ("The Seventh").

While in the Ministry of Security, T'Pol was also involved in mission operations at Tomed near Romulan space. Serving under her was Major Talok. However, unbeknownst to T'Pol, Talok was a Romulan spy disguised as a Vulcan working in league with corrupt Administrator V'Las of the Vulcan High Command. Their goal was to promote the eventual conquest of Vulcan by the Romulan Star Empire ("Kir'Shara").

After her resignation from the Ministry of Security, T'Pol served for over a year as the deputy science officer aboard the Vulcan cruiser Seleya, under the command of Captain Voris ("Impulse").

In 2149, T'Pol began her tenure at the High Command's Consulate on Earth, assisting Ambassador Soval in his observation of humanity's progress toward space exploration ("Fusion"). In 2151, then holding the rank of sub-commander, she was selected by Soval to accompany Captain Jonathan Archer during his initial first mission aboard the Enterprise NX-01 as observer and Vulcan representative. When the mission was successful and the Enterprise greenlighted to continue its mission of exploration, T'Pol elected to remain on board as science officer ("Broken Bow").

Pa'nar, trellium, mind melds, and emotion

T'Pol, who is described by her superiors as a maverick and a rebel, became fascinated with Tolaris, a member of a group of emotionally free Vulcans encountered during the first year of the Enterprise's mission. Tolaris introduced her to the concept of the mind meld, which at the time was considered a taboo activity among Vulcans. She severed her relationship with Tolaris after she asked him to stop the mind meld and he refused, attempting to continue the meld without her consent (essentially a form of mental rape), and causing her to forcefully break the link. She later learned that she had contracted Pa'nar Syndrome from the encounter. This condition was kept in check with medication. In 2154, T'Pol, who had been told that Pa'nar was an incurable virus, learned that the condition was in fact caused by an improperly trained melder, and contrary to what the intolerant (and soon to be overthrown) Vulcan High Command had decreed, it was indeed curable by the touch of an experienced mind – provided to T'Pol by T'Pau.

T'Pol was told that she is genetically incapable of initiating mind melds herself, however following the 2154 overthrow of the Vulcan regime that stigmatized mind-melding she learned otherwise. She performed her first mind meld upon Hoshi Sato, with the assistance of Jonathan Archer, who had learned details about mind melds during a period of time when he held the katra of Surak. In fact, not only is T'Pol telepathic, but the episode "Affliction" revealed that she is able to communicate with Charles "Trip" Tucker III over great distances using her new-found mental abilities. It was established a year later (in "Bound") that this is because of a mating bond between the two.

During T'Pol's early years aboard the Enterprise, she demonstrated an unusual (for a Vulcan) willingness to explore human culture and customs, although she stated that certain human foods do not agree with her. After a discussion with Commander Charles Tucker, she described pecan pie, as a dessert made of "mostly sugar". She began attending the ship's weekly film night social event (with Captain Archer), and expressed particular admiration for the 1931 film Frankenstein. She was reportedly less successful at mastering the art of eating with chopsticks, to the amusement of her crew mates.^[10] Prior to her posting aboard the Enterprise, T'Pol on at least one occasion left the Vulcan Compound in San Francisco and visited a jazz music club; the chaotic music generated an emotional response that came back to haunt her during a brief period when she abandoned her nightly meditation ritual (concurrent with her experimentation with mind-melding).

T'Pol also became adept at "play acting", which she found was often needed in order to successfully fulfill a mission. For example, she once pretended to be a slave when Ferengi pirates hijacked the Enterprise ("Acquisition"), distracted a group of Suliban invaders by acting deranged ("Shockwave (Part II)"), and pretended to be a domineering Vulcan commander preparing for an execution ("Precious Cargo"). In the latter example there is a clear indication that T'Pol enjoyed taking part in this sort of deception.

On several occasions during her first two years aboard the Enterprise, T'Pol resisted efforts by her family and the Vulcan High Command to get her to leave the ship and return to her Vulcan obligations. When pressed for a reason by Vulcan Ambassador Soval, T'Pol replied that she found working aboard the Enterprise "gratifying", for which she was chided for engaging in an emotional indulgence.

In 2153, after being ordered to leave the Enterprise and return to Vulcan, T'Pol resigned her commission with the Vulcan High Command in order to accompany the crew of the Enterprise into the Delphic Expanse to find the Xindi, a mysterious race accused of killing seven million humans on Earth. Despite being technically a civilian, she remained as first officer of the Enterprise and the crew continued to refer to her by her High Command rank of Sub-Commander during the mission.

While investigating the Vulcan ship Seleya ("Impulse"), which had become trapped in The Expanse, T'Pol experienced the side effects of Trellium-D, a compound the ship had used to protect itself from anomalies within The Expanse, but which had the side effect of creating psychosis in Vulcans. T'Pol's brief exposure led to her experiencing extreme paranoia and losing control of her emotions. She recovered upon returning to the Enterprise. The compound, which Commander Tucker brought aboard, was necessary to line the ship so that the Enterprise could traverse the Expanse. Captain Archer, rather than line the ship with the concoction (lethal to T'Pol), stored it in a locker in the cargo bay.

T'Pol found herself wanting to experience more of the emotions the Trellium-D had unlocked. In "Damage", it is revealed that she discovered how to liquefy small, safe amounts of the compound and began to secretly inject herself with it, beginning approximately three months prior to the Enterprise arriving at Azati Prime ("Azati Prime"). This led to what she felt was improved relations with her crew mates, in particular chief engineer Trip Tucker, which led to a sexual relationship in "Harbinger" after she understood she was experiencing jealousy when Tucker began making romantic overtures toward a MACO on board. In the same episode, she later attempted to deflect the importance of the act by referring to it as merely an exploration of human sexuality. However, this one-time encounter resulted in the formation of a psychic bond between Trip and T'Pol which does not manifest until the second half of season 4.

Over time, as T'Pol became addicted to the Trellium-D injections, her emotions began to flow more freely. This came to a head when the Enterprise reached Azati Prime ("Azati Prime") and Jonathan Archer chose to undertake a suicide mission in order to complete the Xindi mission. T'Pol's emotional reaction toward Archer's departure and presumed death incapacitated her as a commanding officer (ending up in crying and an attempt to recover him). She attempted to hide her condition, and the Enterprise was nearly destroyed in a subsequent Xindi attack which may or may not have been made worse by T'Pol's state.

After the attack, T'Pol's supply of Trellium-D became difficult to reach (being located in a heavily damaged part of the ship) and she nearly died during a clandestine attempt to retrieve it. Soon after, she lost her temper with Archer (who had since returned to the Enterprise). He indicated he needed her for a difficult (and morally questionable) mission. She was nearly killed while trying to recover more Trellium-D after experiencing an erotic dream involving Tucker. This led her to seek medical help from Dr. Phlox to whom she confessed her addiction.

Although T'Pol subsequently overcame her addiction, Phlox determined that she had permanently damaged her brain, and as a result might never achieve the same level of emotional control she once had. A subsequent encounter with an elderly version of herself (due to an Expanse-related anomaly seen in the episode "E²"—an alternate universe episode) indicated that she will live with the after effects of her Trellium-D exposure for the rest of her life. The older version of T'Pol served aboard an alternate time line version of the Enterprise, which had been transported into the past. Aboard the alternate Enterprise, T'Pol and Trip Tucker had married and conceived a son, Lorian, who at the time of the encounter was the captain of the alternate Enterprise. The older T'Pol advised her that Trip Tucker could provide a safe outlet for her newfound emotions if she could learn to trust him. She also advised her younger self that she could not imagine what her life would have been like without him. T'Pol did not choose to pursue a romantic relationship with Trip when the Enterprise returned to normal space in the Expanse.

Following the Xindi mission, she continued to experience difficulty controlling her emotions and became particularly emotional following the death of her mother.^[11]

T'Pol, who (at the time) held the record for the longest time spent by a Vulcan serving with humans, has demonstrated her ability to adapt. Originally, she required a form of medication in order to tolerate the odors given off by humans and Captain Archer's pet dog Porthos (because of Vulcans having a sensitive sense of smell).

It's revealed that she has a sense of humor, one she can demonstrate (as she has in "Future Tense" and other shows, including "Bound"). And, in a case of "when in Rome, do as the Romans do," she has also begun eating some types of foods (fruit, popcorn) with her hands, breaking a long-standing Vulcan taboo in the process.

Following the death of her mother (see below), the divorce of her husband Koss and the discovery of the Kir'Shara, T'Pol began to re-evaluate Surak's teachings and what it means to be Vulcan. As a result, she began to distance herself from some of her crew mates, choosing to spend her free time studying the newly found word of Surak. Her decision had an adverse effect on her relationship with Commander Tucker. (In "Bound", she re-established her romantic relationship with Trip. T'Pol asked Trip to return to the Enterprise and, when he replied that he "would think about it" she showed her emotional commitment by pursuing him down the corridor and kissing him.)

She has also experienced some success in controlling her emotions to a greater degree than she had over the two years. T'Pau's therapeutic mind-meld cured the Pa'nar Syndrome and may have helped restore some of her emotional balance as well. This, combined with the fact that T'Pol no longer has the added stress of living with an incurable, potentially fatal condition, may have calmed her mind sufficiently to maintain control. Despite this, she has admitted to Phlox that she had never before felt so unsure of herself.

Relationship with Charles "Trip" Tucker III

The relationship between T'Pol and Trip Tucker is a complex one. Initially, the two had a somewhat combative association.

During the third season of Enterprise, while the ship was engaged in pursuing the Xindi weapon in the Expanse, T'Pol and Tucker became increasingly intimate. This process began because Trip had trouble sleeping. Dr. Phlox urged T'Pol to assist Trip by using Vulcan neuropressure, a system of massage that T'Pol referred to as "intimate" and which is frequently conducted in a semi-clothed state.

A few episodes after this, starting in "Impulse", T'Pol begins to take Trellium-D, which has the result of lowering her barriers and producing greater emotion.

In "Similitude", when Doctor Phlox grows a mimetic symbiote of Trip – complete with Trip's memories – the Sim confessed to T'Pol that he (they?) had a deep attraction to her. In "Harbinger", a few months after Trellium-D usage and neuropressure sessions, T'Pol learns that Trip is attracted to a MACO aboard the Enterprise. T'Pol begins to display signs of jealousy regarding Trip's activities with another woman aboard the Enterprise and Trip is jealous of Sim for having been the one to admit "their" feelings for her – ultimately, she and Trip have sex. Afterward, T'Pol attempts to distance herself from the act by referring to it as an exploration of human sexuality. After they engage in sex in "Harbinger", they do not engage in the act again in season 3.

In "E²", an alternate timeline is revealed where Commander Tucker and T'Pol get married and have at least one child, who they meet, called Lorian. It creates an awkward situation but further illuminates their relationship.

In "Zero Hour", T'Pol reveals her age to him, which she indicated Vulcans consider "intimate" information.

In Home, at the end of the Xindi mission, when Trip tells her he has no home left to go to, T'Pol invites him to accompany her home to Vulcan. After arriving on Vulcan, T'Pol is blackmailed into marrying her original betrothed, Koss, in order to save her mother's career. Her mother, T'Les, realizes Trip is in love with her daughter and suggests to him he should express his feelings to T'Pol before the ceremony so that she could have all available information. Trip declines, saying that she is under enough stress and he cares about her too much to make things even more difficult for her. However, T'Pol was not unaware of his feelings. She paused on her way to marry Koss long enough to give Trip a kiss on the cheek, a scandalous public display of affection for a Vulcan, especially in those circumstances.

In "Kir'Shara," following the discovery of the Kir'Shara in season four, T'Pol's husband divorces her and Trip attempts to reconnect their relationship. T'Pol is studying the original teachings of Surak, and disregards that request. Hurt, Trip decides to make a new start and transfers to Enterprise's sister ship NX-02 Columbia, then working up prior to being commissioned. While he is away on Columbia, both he and T'Pol experience telepathic contact in the form of both waking daydreams as well as dreams while sleeping.

An emergency requires Trip to return to the Enterprise. While he is aboard, an attempted takeover by Orions reveals that Trip is the only human aboard who is immune to the pheromones emitted by the Orion women, which proves to T'Pol they have bonded. An undetermined amount of time after the two learn of their bond, their relationship undergoes a major shock during the Terra Prime episodes when Trip and T'Pol learn that they have a child. The baby was a binary clone created using stolen DNA samples of the two by a terrorist group headed by a radical separatist, Paxton, who believed Earth should distance itself and defend itself from alien worlds and influences. The baby, a girl, was named Elizabeth after Trip's sister. As stated by Phlox, the child has Trip's eyes and T'Pol's ears. Elizabeth does not survive due to a flawed procedure during the cloning process. Trip revealed this to T'Pol when he went to her quarters to try to console her. He further indicated that according to Phlox, a different cloning process performed by gene surgeons who were more highly skilled than those employed by Terra Prime would probably result in a viable child. The two grieved together for Elizabeth, whom they had accepted as theirs.

Relationship with Jonathan Archer

When T'Pol first reported to duty aboard the Enterprise, Archer resented her assignment due to his distrust of Vulcans and the fact that the Vulcans had refused to provide starcharts and a copy of the Vulcan database unless T'Pol was assigned to the crew. T'Pol would butt heads with Archer about his style of command during the ship's early missions, chastising him for taking chances just to be able to explore new planets. As time passed, T'Pol proved to be a valuable asset to Archer due to her time in space and her past experiences as an officer with command experience. Indeed, her command experience is what secured her position as First Officer. As Enterprise's mission progressed, T'Pol grew very close to Captain Jonathan Archer whose abilities she had come to respect and to whom she had developed a sense of loyalty after he assisted her in bringing to justice a renegade Vulcan Security agent. Her sense of loyalty went so far as to compel her to resign her position with Vulcan High Command and join Enterprise without a commission from either Starfleet or the Vulcans during her mission in the Delphic Expanse. During the Delphic Expanse mission, T'Pol continued to serve as First Officer despite her not holding a commission. After the Delphic Expanse mission, T'Pol opted to remain with Starfleet and with Archer's assistance, bypassed Starfleet training, was directly commissioned with the rank of Commander, and was formally assigned as Archer's First Officer. On the occasions when Archer was thought killed, T'Pol showed her affection for him to the point of crying during the Xindi mission when she believes he has been killed in "Azati Prime". She also grieves in "Zero Hour", when she believes he is dead, by holding close a book of his and pets his dog, Porthos.

In one alternate timeline (depicted in "Twilight"), T'Pol devoted her life to caring for Archer when parasites robbed him of the ability to store long-term memory (the same ones with which he was infected while saving her life). Dr. Phlox later implied that T'Pol had fallen in love with Archer during the time that she took care of him.

Starfleet service

Near the end of the Xindi mission, T'Pol revealed to Archer and Tucker that she was considering enlisting in Starfleet. Following the Xindi mission, she accepted the commission and received the rank of Commander. In May 2154, T'Pol officially assumed duties as a Starfleet officer.

The final episode "These Are the Voyages..." reveals that T'Pol remained Archer's first officer aboard the Enterprise for a total of ten years. Her relationship with Trip allegedly ended at some point within a year of the death of their cloned child in 2155 (see "Family", below), although she remained emotionally attached to him and expressed concern that she would never see Trip again after the decommissioning of the Enterprise in 2161. Trip's death on a minor mission just prior to the decommissioning affected her deeply, and she expressed a desire to meet his parents.

She also grew comfortable in confiding in the ship's chef during the years prior to the finale. Dialog in the finale suggests that T'Pol was to be assigned to another vessel following the decommissioning of the Enterprise. In the Star Trek novels released following the formation of the United Federation of Planets, T'Pol was promoted to captain and given command of the newly commissioned NX-class starship USS Endeavour, NX-06.^[12]

Awards

For her performance as T'Pol, Blalock was nominated for a Saturn Award in the category Best Supporting Actress on Television, which she won.^[32] Blalock was again nominated in the same category, three more times.^[33]