Season 2, episode 26. The Enterprise is ordered to travel back in time to 1968 Earth in order to monitor their communications and study how they survived desperate times. They have their deflector shields up so they will not be detected. The ship shakes violently and Mr. Spock calls to Kirk that something or someone is trying to beam aboard the ship which is seemly impossible because the technology was not developed in 20th century Earth. That transporter beam from where it originated is at least 1,000 light years away and as Scotty reminds Spock that is impossible, not even in their own century can a transporter beam reach that far - but it has happened. Kirk arrived to the transporter room only to find that Mr. Spock is correct - a man beams aboard holding a black cat named Isis, agent Gary Seven. Agent Seven tells them he is from 20th century Earth and was on another planet when they intercepted him, to step back and let him do what he must do in order to accomplish his mission or it will alter Earth's history and maybe even the lives The Enterprise - the future altered. Kirk is in a dilemma, what if all Gary Seven says is true? Bu what if he's lying and really an alien from the future trying to destroy Earth? Kirk must find out before he can let Seven go - that will require a medical examination, all the crew's help in analyzing how Seven got on the ship and for Kirk & Spock to beam down to 20th century, 1968 Earth.
A most interesting episode captain. It deals with Earth's technology progressing faster than it's social and political maturity. Time travel, possible future aliens, secret agents, 1968 Earth, the prime directive, a black cat that Spock is strangely attract to and Kirk's suspicions over Gary Seven.
9/10
