Dr. Tristan Adams
Dr. Simon Van Gelder
Dr. Helen Noel
left the Tantalus V penal colony after a routine visit, a stowaway is
discovered aboard the Enterprise which turns out to be Dr. Simon Van Gelder,
a former director of the colony. Kirk contacts the current director, Dr.
Adams, and is informed that a failed experiment was responsible for Van
The Enterprise returns to the planet and Kirk beams down with Dr. Helen
Noel to examine the facility. They are given a tour and shown the machine
which caused Van Gelder's condition - a 'neural neutraliser' - that, they
are told, is now functional but only capable of relaxing agitated inmates
for short periods of time.
Kirk is sceptical and, during the night, he and Dr. Noel secretly test
the machine. They discover that it is much more powerful than claimed
when, even on a low setting, Kirk finds he is compelled to follow suggestions
made to him by Helen Noel, who is operating the device. They are discovered
there and Noel is captured by Adams, leaving Kirk at his mercy, strapped
in the neural neutraliser. Adams plants the suggestion in Kirk's mind
that he is madly in love with Helen, following which he becomes absolutely
besotted with her.
They are unable to contact, or be rescued by, the Enterprise crew due
to a security force field that has been thrown up around the facility.
Dr. Noel is finally able to convince Kirk of their duty and he allows
her to leave him and shut down the power supply generating the force field.
During the period of their captivity Spock had been busy aboard the Enterprise.
Mind-melding with Dr. Van Gelder, he has learned that the doctor had been
brain-washed by Adams but has been unable to contact the captain to advise
him of the fact until Noel shuts down the force field.
While Helen Noel is on her sabotage mission, Kirk fights with Adams, knocking
him unconscious and leaving him in the chair of the neural neutraliser
while he escapes. When power is restored to the colony the machine activates
at full strength. With no-one at the controls to place suggestions to
him, Adams' mind empties completely, causing his death.