Lieutenant Saavik is a fictional character in the Star Trek universe. She appeared first in Star Trek II: The Wrath of Khan, in which she was played by Kirstie Alley. She was also a supporting character in Star Trek III: The Search for Spock, and appeared briefly in Star Trek IV: The Voyage Home; in these movies she was played by Robin Curtis. Of the various characters created specifically for the 10 Trek films, she is the only one to appear in three of the movies.
A few sources have her (non-canon) origin story as follows: she was rescued from the colony, along with other children, by Spock, and she was adopted by his parents Ambassador Sarek and Amanda Grayson. Following in the footsteps of her adoptive brother and role model Spock she entered Starfleet Academy. In the non-canon 1990 novel Pandora Principle, by Carolyn Clowes, it is established that four Vulcan research ships were captured by Romulans. Their Vulcan crews were abducted by Romulan scientists and their fertility was manipulated to produce half-Romulan, half-Vulcan children such as Saavik to use in mind control experiments. Vulcan scientists learned of the experiments and mounted a secret rescue of Saavik and other child survivors on Hellguard. Spock threatens to reveal the story to Federation authorities and along with it the secret of the Vulcan mating cycle pon farr if the survivors aren't given Vulcan citizenship. Other members of the party want to educate them elsewhere and send the children to live on worlds other than Vulcan. Clowes writes that Saavik's name is of Romulan origin and means "little cat." In Pandora Principle, Saavik, unlike the other half Vulcan, half Romulan child survivors, refuses a DNA test that would identify her Vulcan relatives. Instead, Spock, who has established a bond with her, takes a year of personal leave to "civilize" and educate the 9- or 10-year-old Saavik. She then lives off Vulcan with foster families or at boarding schools chosen by Spock until she is accepted into the Starfleet Academy as a teenager. This agrees with the Star Trek III: The Search for Spock novelization which said Saavik has never been to Vulcan until then. After graduating, as a fresh Lieutenant Saavik was on her cadet cruise on the USS Enterprise with Admiral James T. Kirk and Captain Spock when Kirk's old enemy Khan Noonien Singh sought revenge and attacked the Enterprise.
Spock died while saving the Enterprise during the events of Wrath of Khan, but before his death transferred his "katra" to Dr. Leonard McCoy (see Vulcans for more information on this ability). His coffin was fired from the Enterprise in orbit around the Genesis Planet and was believed to have been destroyed in the atmosphere. A rare expression of emotion by a Vulcan is displayed when Saavik is seen shedding a tear during the eulogy for Spock by Kirk. Saavik and David Marcus (son of Admiral James T. Kirk), subsequently were assigned to the research vessel USS Grissom to study the newly formed Genesis Planet. During this mission, Saavik discovered that Spock had somehow been regenerated, and was rapidly aging. As the new Spock entered his teenage years, he began experiencing the mating drive known as pon farr, and Saavik helped ease Spock through this difficult time. When the Klingon commander Kruge and his men capture the landing party the next day, David sacrifices his life to save Saavik from being executed. Saavik helped Admiral Kirk return Spock to Vulcan where his body and katra were reunited. After that, she remained on Vulcan with Spock's family for reasons never explained on screen; the film's writers intended that this was because she was pregnant with Spock's child as a result of the pon farr, but no references to her pregnancy made it into the finished movie and it was never followed up, thereby once again placing this development into a grey area in terms of canon.
A significant character in Star Trek VI: The Undiscovered Country was a young female Vulcan protege of Spock, who turned out to be working with the villains. In an early draft of the script, this was Saavik, in the hopes that Alley would return for the large role, using characters that had appeared in prior films (even in small parts) turning out to be significant players this time. Alley turned down the role and they instead created the character of Valeris, played by Kim Cattrall. Some sources, however, suggest the reason for the change was that Gene Roddenberry objected to the popular character becoming a villain and vetoed it. The studio also was reportedly not keen on having three different actresses playing the same role. The novelization of this film actually includes a sequence in which Valeris, newly appointed to the Enterprise, meets Saavik, but its not known if such a scene was ever planned for the movie.
The character was at one point to appear in the Star Trek: The Next Generation episode, "Cause and Effect" in a scene in which the Enterprise-D encounters a starship that had been trapped in a time anomaly for some 80 years. The idea was dropped when Kirstie Alley insisted on being paid more for a nonspeaking cameo part than the episode budget could supply. (Saavik was to have been shown standing alongside a character played by Alley's Cheers co-star, Kelsey Grammer).
Kirstie Alley did play Saavik one other time, in a play set between ST II and ST III. "The Machiavellian Principle" written by Walter Koenig for the ambitious "Ultimate Fantasy" convention. It also starred DeForest Kelley, James Doohan, Walter Koenig, Nichelle Nichols and George Takei, with a walk-on role by William Shatner as "the Admiral". The script, as published by Creation Conventions in a 1987 booklet called "Through the Looking Glass", misspells the name as "Savik". Star Trek books are not considered part of the established canon.