TOS s2e3 “The Changeling”

He said the thing! Of course, Nomad is able to revive Scotty minutes later. What’s fucked up is that it also erased Uhura’s mind, but couldn’t restore her memories. The solution? Oh, we’ll just re-teach her everything. She won’t remember a damn thing about her former self or even possibly have the same personality, but hey, she can still do the job! And as with all TV magic, by the next episode it’s like it never even happened.