Troi was initially underutilized, but her radical empathy made her a vital part of the show.
Nicholas Meyer originally wanted Kirstie Alley back as Saavik, but things clicked with Kim Cattrall.
Ilia would have been a permanent addition to the Enterprise crew in Star Trek: Phase II.
Early drafts featured a Vulcan who kept changing sex, two young women who were attracted to older men and a navigation officer who was part polar bear.
Creating Spock’s pointed ears involved a lot of work — and a lot of pain for Leonard Nimoy.
Although he had no part in selecting Ricardo Montalbán to play Khan, Nicholas Meyers had no complaints.