You had your chance, Captain Kirk. You should've smothered the life in me. Then they would have said Dr. Janice Lester died of radiation poisoning in the line of duty. Why didn't you do it? You always wanted to. Didn't you? You had the strength to do it. But you were afraid. You were always afraid. Now Janice Lester takes the place of Captain Kirk. I already possess your physical strength. Only this Captain Kirk is not afraid to kill. Now you know the indignity of being a woman. For you, this agony will soon pass, as it has for me. Quiet. Quiet! Believe me, it's better to be dead than to live alone in the body of a woman. It's better to be dead.
~ Lester, after switching bodies with Kirk

Dr. Janice Lester is the villain of "Turnabout Intruder", the final episode of the original Star Trek series, which would also make her the series' final antagonist.

She was played by Sandra Smith while in her own body and by William Shatner while in Kirk's body.


Lester is known to hate being a woman, which she believes is the reason she couldn't achieve her dream of commanding a starship. She was also a former lover of James T. Kirk's, and it's implied that her jealousy of Kirk ended their relationship. At some point, she became the leader of an archaeological expedition on Camus II. After discovering a machine which swaps consciousnesses, Lester and Dr. Arthur Coleman murdered the rest of the expedition in order to lure the Enterprise to the planet. While alone with Kirk, she used the machine to swap herself into his body.

As Kirk, Lester took over as captain of the Enterprise. She tried to suppress the real Kirk, who was inside her original body, but Spock got to him and did a mind-meld; this convinced Spock of the truth. Spock's conviction and Lester's increasingly obvious lack of leadership ability turned much of the crew against her. Eventually, the transfer broke, leaving Lester and Kirk to float back into their original bodies. Kirk felt sympathy for her at the end and had Lester escorted to Sickbay.

Coleman and Lester were taken in to custody. Upon arrival at Starbase 2, Lester was transferred to the custody of station security. After facing criminal charges for her actions, she was transferred to the Elba II asylum. Captain Kirk would later describe the time he spent living in Lester's body as educational.

Lester is likely a psychopath, given her apparent lack of remorse for murdering her expedition and willingness to commit further murders. However, she was unable to kill Kirk due to still having feelings for him.


I hoped I wouldn't see you again.
~ Lester's first lines
The year we were together at Starfleet is the only time in my life I was alive.
~ Lester, to Kirk
Your world of starship captains doesn't admit women. It isn't fair.
~ Lester, to Kirk
I loved you. We could've roamed among the stars.
~ Lester, to Kirk
Love? Him? I love the life he led. The power of a starship commander. It's my life now.
~ Lester
James Kirk is returning to consciousness in the body of Janice Lester. The Enterprise is proceeding to its next mission, on the course set before I took over command. Now the years I spent studying every single detail of the ship's operation will be tested. With a little experience, I will be invulnerable to suspicion. At last, I attain what is my just due--command of a starship. All the months of preparation now come to fruition.
~ Lester's captain's log
Violence by the lady, perpetrated on Captain Kirk? I ask the assembled personnel to look at Dr. Janice Lester and visualize that historic moment.
~ Lester
Are you prepared with witnesses? One will do.
~ Lester, to Kirk
And with the truth revealed, that I am not really the captain, and knowing that she would not be allowed to serve as the captain, then you would be the captain! It is inevitable!
~ Lester, to Spock
It is mutiny! Deliberate, vindictive, insane at its base! But mutiny is charged, and encouragement to mutiny. Dr. McCoy, Mr. Scott, you heard it! On the basis of these statements, I call for an immediate vote, by the powers granted to me as captain of the Enterprise.
~ Lester
Silence. You will be silent!
~ Lester, to Spock
I will not go back to being Janice Lester. You must help me prevent it.
~ Lester, to Coleman
Kill him! Kill him!
~ Lester
Ohh! I've lost to the captain. I've lost to James Kirk! I want you dead! I want you dead! I want you dead! Oh, I'm never going to be the captain. Never. Kill him.
~ Lester, after the transfer reverses