Lieutenant Valeris was a Starfleet officer who served aboard the USS Enterprise-A as helm officer in 2293.
Mentored by Spock, she had been the first Vulcan to graduate at the head of her Starfleet Academy class.
Valeris was involved in the Khitomer conspiracy, which tried to sabotage the Khitomer Conference between the Klingon Empire and the United Federation of Planets in 2293. Her involvement in the plot stemmed from a resistance to the changes peace between the Federation and the Klingons would bring. She contributed to Captain James T. Kirk and Dr. Leonard McCoy's imprisonment by providing the Klingons Kirk's personal log about how he disliked them for the death of his son. She also killed the two officers who killed Chancellor Gorkon, using a phaser at point-blank range, to avoid alerting the rest of the crew, who were searching for evidence about the conspiracy aboard the ship.
However, Valeris made a mistake when she was tricked into thinking that the men she killed were still alive, which was actually a trap to expose her. Spock was able to retrieve information from Valeris by using a forced Vulcan mind meld, the conspiracy was uncovered and the assassination of the Federation Council President was prevented, thereby saving the Khitomer Conference and paving the way for nearly 100 years of peace between the Klingon Empire and the Federation.
Lieutenant Valeris was taken into custody and later charged with treason. (Star Trek VI: The Undiscovered Country) Template:EnterpriseHelmsmen
Appendices
Background
Saavik was to have reprised her role in Star Trek VI: The Undiscovered Country, 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. Also, no one wanted to have to cast a third actress to play the same role.
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. (I Am Spock) The shooting script spells the name "Val'eris", but the apostrophe doesn't appear in the closing credits 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.