Text from Nichelle Nichols’ biography “Beyond Uhura”
Usually, though, Leonard remained Vulcan-cool. Perhaps the most elaborate hoax involved his son, Adam, who about eight years old while we were filming the original series. It required that Adam be fitted in a child-size Starfleet uniform and be made up, ears and all, to look just his daddy.
The script called for a scene on the bridge in which Spock would be sitting in the captain’s chair with his back t o the elevator door. A yeoman was supposed to enter and say some lines, at which point Spock was to spin around in his chair, so he was facing the yeoman, and continue their brief exchange.
They had Leonard’s son, in his Vulcan disguise, waiting in the elevator. The door opened, Adam delivered the yeoman’s lines, then Leonard turned to him and answered without breaking a smile or missing a beat.
We couldn’t get so much as a Spockian arched eyebrow out of Leonard. The real kicker came when Adam “stepped out of character,” so to speak, to say, “But, Daddy, I love you.”
“Thank you, Adam,” Leonard said evenly. As the whole cast and crew stood around in breathless anticipation of Leonard’s big crack-up, which never came, by the way, the joke was on us.