The main reason for introducing new characters in Star Trek II was that Leonard Nimoy had said he wanted to leave the franchise. Hence the need for a new science officer, called Saavik. Or, before the character was changed into a woman, Savik.
Savik first appeared in Jack B. Sowards’ script, which was based on a draft by Producer Harve Bennett. Bennett was the one who came up with returning Khan; Sowards suggested that Nimoy might be persuaded to return to Star Trek one more time by giving him the opportunity to play Spock’s death. (He was right.)
By this time, Vulcan culture had not yet been well defined, which explains why Sowards gave Savik a sense of humor. The young science officer even made a few jokes at Kirk’s expense.
Other new characters included a Lieutenant Charles Waters at weapons, replacing Chekov (who had transferred to the Reliant), and a Diana O’Rourke at communications, replacing Uhura (it is unclear what happened to her).
O’Rourke was a young woman attracted to Kirk. She would spend her spare time reading up about the famous starship captain, and comforted him after Spock’s death.
Neither Waters nor O’Rourke made it into the next and third draft by Samuel A. Peeples.
Peeples’ script was reminiscent of the episode he had written for The Original Series, “Where No Man Has Gone Before”. He replaced Khan with two god-like creatures and added two new characters to the Enterprise crew, Thal Arctos and Uti Sorbayo.
Few of Peeples’ ideas made it into the movie, except that he made Savik a woman, initially spelled “Ssavik” before settling on the now-familiar “Saavik”. She was to be half-Vulcan and half-Romulan, the result of Spock’s encounter with the Romulan commander in “The Enterprise Incident”. The commander would have artificially inseminated herself with Spock’s genetic material and then sent her daughter to be raised on Vulcan.
Saavik’s dual nature would have been a source of drama. “With her there is a constant torment,” Peeples wrote in his notes, “an eternal struggle for dominance between the two sides of her nature.” She used logic, but unlike full-blooded Vulcans wasn’t ruled by it.
Thal Arctos, from the Latin word for polar bear, would have been the new navigation officer. Despite his polar-bear DNA, he would have appeared mostly human, except taller, more muscular and with snowy white hair.
In one scene, Arctos stole a refrigeration unit from engineering so he could have an ice bath. Like Kirk, he was something of a womanizer. His favorite pastime was whispering Elizabethan poetry into women’s ears.
Peeples’ third new character was another beautiful women called Uti Sorbayo. A doctor of East Indian descent, she fell in love with Dr McCoy. More interestingly, she was religious, which would have been unusual for Star Trek.
Director Nicholas Meyer, who took Bennett’s, Sowards’ and Peeples’ scripts and combined them into his own, eliminated all the new characters except Saavik, whose heritage he left undiscussed.