Kirk, Spock and McCoy suddenly find themselves in an underground laboratory where they meet an attractive young woman who is not only mute but also an empath who can absorb someone else's pain. When their captors make themselves known, they refuse to explain why the three men have been taken prisoner or why they and the young woman, whom McCoy has named Gem, are there. Inexplicably, they set about torturing them for no apparent reason. Fortunately, Gem's empathic powers allow her to take away their pain, but only at great sacrifice to herself. When their captors tell Kirk that he must choose which of his men to die, their selflessness comes to the fore, leaving Dr. McCoy volunteering himself. They all soon learn that the object of the experiment is Gem herself. Written by
Did You Know?
This episode contains another one of McCoy's famous, "I'm a doctor, not a..." quotes. In this episode it is "coal miner". See more
The first time Kirk, Spock and McCoy are hit with the Vian force field, Kirk says he "can't seem to stand up", even though he is standing. See more
Don't fight the force field. There's something about it that upsets the body metabolism.
Not quite, Doctor. The field draws its energy FROM your bodies. The more you resist, the stronger the force field becomes.