We laughed and we joked, and so far we hadn’t even gotten to the reason why I was there…Finally they said, ‘This has really been wonderful,’ and they asked me to read for them. I said, 'I’d love to.’ They handed me a script and apologized, saying the part I’d be playing would be the communications officer, but that they were changing the whole role, that there was nothing for me to read, and would I read this part here, because that would probably be close…
And I said, 'Oh, well, tell me about this Spock person, what does she do?’ And they explained, 'Oh, wait a minute, you’re not reading for Spock now. Spock is male and has already been cast. We just felt in order to get a feeling…’ I said, 'Why don’t you tell me about the character, the person, and I can read it as if I’m going after that role, and you can see if I can act.’
Joe Sargent said, 'That’s a great idea…He’s half-alien, has green blood, and he’s totally logical about everything.’ I said, 'What do you mean he’s half-alien?’ They said, 'His mother’s an earthling,’ and I said, 'Well, then he doesn’t have total logic,’ and we laughed about that.
So I read for the role, pretending I was up for the part of a female Spock…When I finished, one of the guys said, 'Call down to personnel to see if Leonard Nimoy has signed his contract yet.’ Of course, they knew he had, but that was their charming way of telling me that I had really done a good job.
Nichelle Nichols describes her audition for Star Trek in front of Gene Roddenberry, Joe Sargent, Eddie Milkis, and Gregg Peters. From a 1987 interview printed in The Star Trek Interview Book by Allan Asherman.