Valeris Lieutenant Valeris was a female Vulcan Starfleet officer of the 23rd century . She served as helmsman aboard the , during its mission to escort the Klingon Chancellor to Earth in 2293 . In that capacity , she was a key participant in a conspiracy to sabotage peace talks between the Klingon Empire and the Federation . History . Valeris was mentored by Captain Spock at Starfleet Academy , and became the first Vulcan to graduate at the top of her class . Spock took interest in her career with " satisfaction " as she eventually attained the rank of lieutenant . Valeris requested to be assigned to the " Enterprise " - A upon learning of their need for a helmsman . Spock , having been impressed with her , informed her of his intentions to retire subsequent to the completion of their diplomatic mission , and of his desire that she should fulfill his role aboard the ship . Khitomer conspiracy . Valeris did not consider it logical to attempt peaceful interactions with the Klingon Empire , considering the Klingons untrustworthy . Before coming to the " Enterprise " , Valeris had committed to the Khitomer conspiracy on the Starfleet side . Upon establishment of contact with the chancellor ' s flagship , Kronos One , Valeris suggested to Captain Kirk the service of Romulan ale during a dinner which the " Enterprise " crew was hosting for Chancellor Gorkon and his party . Later , after Kirk and Doctor McCoy were placed under arrest for Gorkon ' s murder , Valeris supplied her compatriots in the Klingon Empire with a recording from Kirk ' s personal log , in which Kirk admitted that he held the Klingons personally responsible for the death of his son , which became a damning piece of evidence in their subsequent trial . Spock ordered Valeris to conduct a search for evidence of the conspirators on the ship . She helped to uncover a few facts and the boots that the assassins wore . Covertly , she also personally murdered Yeoman s and Samno , her fellow conspirators and Gorkon ' s actual assassins , in an attempt to eliminate them as witnesses . After the " Enterprise " crew ' s successful rescue of Kirk and McCoy from the Klingon prison planet Rura Penthe , Kirk and Spock set up a sting operation in an attempt to uncover the conspirator aboard the ship , by announcing that Burke and Samno had , in fact , survived the murder attempt , and were recuperating in sickbay . Their ruse proved successful , leading to a confrontation with Valeris when she made another assassination attempt . She was taken to the bridge and interrogated by Kirk in front of the crew for details of the conspiracy . Valeris refused to cooperate , instead appealing to Kirk ' s distrust of Klingons . In response , Spock forced a mind meld on her , during which he was able to learn of the involvement in the conspiracy of Starfleet Admiral Cartwright , Klingon General , and Romulan Ambassador Nanclus . She was not aware of where the Khitomer Conference was to take place , but did know of another assassination attempt that was to occur there . Hikaru Sulu instead informed them , and joined with them at Khitomer . There , Valeris was taken to the conference to show everyone they could prove the conspiracy . ( ) Appendices . Background information . Saavik was to have reprised her role in , but was replaced with Valeris , reportedly because Gene Roddenberry was concerned that fans had become so fond of Saavik that they would react negatively to her turning out to be a traitor . In addition , no one wanted to have to cast a third actress to play the same role : Kirstie Alley had declined to return , and Nicholas Meyer was not a fan of Robin Curtis ' s portrayal . While referred to as " lieutenant " , Valeris wore the rank insignia of a lieutenant commander . Her Starfleet uniform jacket had the gray insignia patch and wristband of a sciences division officer , but her uniform undershirt was red ( denoting a cadet or student officer ) . This mismatch was caused because no new uniform pieces were being made and the wardrobe department simply found Cattrall existing items that fit her . Robert Fletcher ' s uniform notes specify that an officer ' s collar and uniform patch should match , so a division specialty color could have been added as a strip on her shoulder patch and wristband . " Kim Cattrall designed her headband , suggested her hairstyle and even helped in naming the character – after Eris , the Greek goddess of strife , hinting at Valeris ' role in the events of the film . The " Val " prefix was added to make it sound more Vulcan , contradicting , however , the typical naming convention for female Vulcans ( T ' Pring , T ' Pol , and T ' Pau , for example ) . ( " I Am Spock " ) The shooting script spells the name " Val ' eris " , but the apostrophe doesn ' t appear in the closing credits , DVD subtitles or publicity materials . Cattrall studied the life of Che Guevara when she prepared for playing her role , according to an article by Mark A . Altman . Apocrypha . The novel " Cast No Shadow " depicts Valeris ' life both before and after " Star Trek VI : The Undiscovered Country " , when she is offered a chance at relocation to a colony world under a new name , seven years after her arrest and imprisonment , in exchange for assisting in an investigation into what appears to be a new branch of the Khitomer Conspiracy as the last known living member of the scheme . During the events of the novel , she is forced to acknowledge that the real reason for her participation in the conspiracy was not her logical assessment that the Klingons would be a future threat to the Federation , but her own past trauma from a time she was taken hostage as a child by Klingons attempting to convince her ambassador father to abandon a planet that was negotiating to join the Federation . At the conclusion of the story , she risks her life to disable a bomb that would have decimated the remains of Praxis and the Klingon homeworld , and is given a pardon and a new life on a colony world under the new name T ' Leris . The mirror universe Valeris appeared in the novel " The Sorrows of Empire " . Assigned to assassinate , she is killed by before she can do so .