| The U.S.S. Enterprise arrives
in orbit around Exo III, to search for exobiologist Dr. Roger Korby.
When Kirk asks Spock if Korby could possibly still be alive, Spock
glances at Christine, then quietly shuts off his monitor. Christine
Chapel, McCoy's chief nurse,
is Korby's fiance. Chapel had signed on with the U.S.S. Enterprise in
hope of finding him. Korby is known as the "Pasteur of archeological
Korby's request, only Kirk and a very excited Christine Chapel beam
down to the planet. They find the doctor living in an underground
cavern built by what is known
as "The Old Ones," the extinct natives of Exo III. He tells them that
he discovered the caverns while suffering from severe frostbite, five
equipment left behind by these now-dead beings, Korby has learned how
to construct androids who
look and act like humans. His android companions, Ruk and Andrea, amaze
Kirk and Chapel with their realness. Although, Korby explains, Ruk
long before he arrived — a product of "The Old Ones."
recognizes Dr. Brown, Korby's aide, but is mystified by his failure to
recognize her. The reason for his behavior becomes clear when they
discover that he, too, is a sophisticated android. Korby's plan is to
slowly replace key people in the Federation
with androids, integrating the machines into other worlds.
prisoner, Korby creates a perfect duplicate of the Captain, which fools
even Nurse Chapel. During the duplication process, however, Kirk plants
false memories and ideas in his double's brain which makes Spock
realize that something is
very wrong. Korby, convinced that his android will fool the U.S.S.
Enterprise crew and allow him to take over the starship, has the double
beamed aboard. The false Kirk is to look over their proposed route and
pick a likely planet on which to begin colonization.
immediately becomes suspicious of his captain until finally, after
spewing an ethnic slur at the first officer, Spock is certain that this
is not Captain Kirk. He orders a landing party to meet him in the
transporter room after the Captain has beamed
down to the planet. Meanwhile, on Exo III, Christine Chapel realizes
somehow Roger Korby has changed; he's no longer the wonderful man she'd
fallen in love with. He's become somehow distant and unfeeling ...
though he obviously still has a great fondness for his fiancee.
Christine, Kirk is
being guarded by Ruk. The Captain convinces the hulking android that
is a threat to his continued existence and must be destroyed. Ruk
Korby and is eliminated. It is discovered, to Christine's horror, that
has housed his essence inside an android body. Kirk convinces the
that he's become more machine than human. In front of his horrified
Korby grabs Andrea and fires a phaser blast that kills them both. Spock
arrives with a landing party to find only Kirk and Christine remaining.
Chapel announces that she would like to stay with the U.S.S. Enterprise
to complete her tour.