Star Trek episode "Return to Tomorrow"

"Return to Tomorrow"

Season 2, Episode 20.

A distress call brings them to an alien planet of telepaths, with prophetic words about all mankind perishing. Kirk's log will take three weeks to get to Starfleet at this distance.

The powerful-enough alien named Sargon turned off the power of the entire Enterprise in order to communicate that Spock should beam down too, yet the alien talks other times.

Dr. Ann Mulhall (played by the actress that plays Dr. Pulaski in The Next Generation) is an astrobiologist that comes along.

Sargon keeps calling Kirk's crew "My children" saying that 6,000 centuries ago they were colonizing the area. His race could be the Adam and Eve.

These aliens are now just thought, disincorporated from any body. Then Sargon takes over Kirk's body. They want to borrow the bodies in order to build robotic bodies. The crew agree to it!

Spock says, "With their knowledge, mankind could leap ahead 10,000 years." They never even ask Starfleet about this. We find that the alien that takes over Spock's body is jealous of Sargon's love for the female alien. Spock sabotages the injection for Kirk's body (Sargon). Bones gets to say "He's dead" over Kirk's body.

They start to feel that the bodies would be much better than the robot bodies as they apparently want to feel (and I think that all the aliens want to "feel" Dr. Mulhall's body). They fight it all out, blah blah blah, and the aliens fight amongst themselves.

Although, it does bring up an interesting point: if an alien race could take over the body of a Starfleet officer like this, what could prevent them from really wreaking havoc? If all three of these aliens had been malevolent instead of just the one, the Enterprise would have been easily and completely taken over. They should have lost this round. I guess it will make Kirk think twice about loaning out the bodies of his crew.