In answering a medical emergency at an archaeological expedition, Kirk confronts the deep hatred of an old love, Janice Lester, who supposedly lies severely ill from celebium radiation. In payment for jilting her back at Starfleet Academy, Dr. Lester arranges for an alien machine to swap her consciousness with that of the captain and takes command of the Enterprise. Once aboard, Kirk (in Lester's body) tries to convince Spock that he is trapped in her body. As a result, Janice (in Kirk's body) conducts a court-marshal with the intent of executing Spock and Kirk (in Janice's body), and later McCoy and Scott, to keep her secret. The crew realize something is seriously wrong with their captain and, not wishing to incur an illegal death-penalty themselves, begin a passive resistance. Written by
Did You Know?
The transposition sequence was the last footage shot for The Original Series. See more
When Spock and McCoy are conversing in sickbay, McCoy is wearing his medical garb. However, in the first couple of close-ups, his shirt changes to his regular uniform. See more
I won't become a murderer.
Dr. Janice Lester
[in Kirk's body
You ARE a murderer! You knew it was celebium; you could have treated them for it. You're a murderer many times over!
Spoofed in Kim Possible: Mind Games