Responding to a distress call from far beyond where any Federation vessel has been before the Enterprise comes to a lifeless planet. Here a disembodied voice tells them that he is Sargon and requests that they beam down to coordinates he has provided deep within the planet. He also appears to have selected the members of the away team, when Kirk suggests Spock remain behind the Enterprise suffers a power failure; Dr Ann Mulhall, an astrobiologist, turns up to the transporter room claiming to have received orders; and the two security officers are left behind. It turns out Sargon is a being of pure energy; a consciousness stored in a glowing sphere. He 'possesses' Kirk and explains that he and two similar fellow survivors must occupy the bodies of Kirk, Spock and Mulhall so they can build androids to act as permanent hosts. There are two problems; while possessed the human bodies are put under potentially dangerous stresses and one of their number has decided he would rather keep Spock's body than live in an unfeeling android body.
This is an entertaining episode even though it was clearly cheap even by the standards of the series; we don't see the surface of any strange planets, there is no alien makeup and most of the action takes place in a few rooms on the Enterprise. It is the fact that the dangers come from aliens possessing the bodies of crew members that the danger somehow seems more real; we might know that Kirk and Spock will ultimately survive but the same can't be said for the previously unseen Mulhall; even Kirk didn't seem to know who she was! The cast do a fine job playing the possessed characters; Shatner hams it up delightfully and guest star Diana Muldaur is good as Mulhall but it is Leonard Nimoy who steals the show as we see his normally emotionless Spock start smiling in a most creepy fashion while possessed by the entity Henoch. Overall a pretty good episode.
This is an entertaining episode even though it was clearly cheap even by the standards of the series; we don't see the surface of any strange planets, there is no alien makeup and most of the action takes place in a few rooms on the Enterprise. It is the fact that the dangers come from aliens possessing the bodies of crew members that the danger somehow seems more real; we might know that Kirk and Spock will ultimately survive but the same can't be said for the previously unseen Mulhall; even Kirk didn't seem to know who she was! The cast do a fine job playing the possessed characters; Shatner hams it up delightfully and guest star Diana Muldaur is good as Mulhall but it is Leonard Nimoy who steals the show as we see his normally emotionless Spock start smiling in a most creepy fashion while possessed by the entity Henoch. Overall a pretty good episode.