Simon van Gelder of
staff at the Tantalus Penal Colony escapes to the U.S.S.
signs of manic insanity, an enraged McCoy insists that
Kirk investigate the colony. The Captain reminds McCoy of Tantalus'
reputation, but McCoy is unconvinced.
and Dr. Helen Noel,
the U.S.S. Enterprise's psychiatrist, tour the facility. They discover
the Colony director, Dr. Tristan Adams, has been using a brainwashing
the neural neutralizer, to control not only the colony's inmates, but
staff as well. When the doctor realizes that Kirk has discovered his
he convinces the captain to try the machine for himself, to prove that
is perfectly safe. The result is that Kirk falls madly in love with
Helen Noel and the two remain on the Colony as Adams' prisoners.
on board the
U.S.S. Enterprise, van Gelder is in such a distraught state from the
conditioning that he is unable to explain to Spock what is going on at
penal colony. The Vulcan attempts a mind-meld with van Gelder and
discovers what has been happening on the planet below. On Tantalus, Dr.
through an air-conditioning duct to the power room, where she lowers
planet's defense shields, enabling Spock to beam down a security team.
to fight Adams, who falls into his torturous machine. Weakened by the
and his fight with the doctor, Kirk stumbles away, not knowing that
is still in the neutralizer. Adams is later found dead. Dr. van Gelder
made sane again and returns to direct the Tantalus Colony.