in orbit around the planet Beta III in system C-111 the crew of the Enterprise
try to find some evidence to explain the disappearance of the starship
'Archon' over a hundred years previously. A landing party beams down to
investigate further but on their return Sulu exhibits a strange, vacant
expression and another crew member, O'Neil, is missing.
Kirk and Spock take another landing party down and, on arriving, are puzzled
by the vacant looks on the inhabitants faces, similar to that on Sulu's.
A clock strikes six and everybody around them suddenly goes berserk in
a weird orgy of sex and violence. The landing party find shelter indoors
where they meet three older men who enquire why they are not taking part
in the 'festival'. Kirk replies that they are strangers visiting the area.
One of the men, Reger, offers them accommodation but another, called Halcom,
disappears to inform the Lawgivers about the newcomers. Twelve hours later
the activities of the 'festival' cease as suddenly as they had started
and people act as if nothing had happened. Kirk queries what is happening,
which makes Reger and the third man, Tamar, realise that the newcomers
are 'not of the body'. At that moment two hooded Lawgivers arrive and
order the Enterprise crewmembers to go with them. Kirk flatly refuses,
causing the Lawgivers to pause while they commune to receive further advice.
This gives Reger and Kirk's people the opportunity to make their escape
but they are pursued by a group of local inhabitants until Reger pulls
them into an old building. He reveals that he is a member of an underground
movement consisting of people who are immune to the mind control apparent
in the others.
While he is talking a holographic image of a man-like being appears on
the wall, identifying itself as 'Landru' and tells them that they will
be absorbed into 'the body'. A sonic beam of some kind knocks Reger and
the members of the landing party out and, when they awake, they find themselves
in a prison cell. Shortly, they are reunited with McCoy and the previously
missing O'Neil who are now exhibiting the same vacant expressions as the
An official called Marplen arrives with two Lawgivers who have come to
take Kirk away for treatment. As they leave, Marplen reveals that he is
a friend and returns two confiscated phasers to Spock. They overpower
the Lawgivers and manage to find their way to Landru's 'audience chamber'.
The holographic projection, which Spock and Kirk now realise is a computer-generated
image, appears but weapons appear to be useless against it.
Kirk converses with it and ties it up in logical knots, finally convincing
it that, by stifling creativity, it is destroying the 'perfect society'
it was designed to oversee. The machine, unable to reconcile the paradox,
destroys itself, releasing all the affected people from the mind control
it had imposed and leaving the hooded Lawgivers helpless and confused.