When the planet Sarpeidon is about to be destroyed, by its star Beta Niobe becoming a supernova, Kirk (William Shatner), Spock (Leonard Nimoy) and McCoy (DeForest Kelley) beam down and find it evacuated except for its librarian, Mr. Atoz (Ian Wolfe), tending to his replicas. They are a collection of unusual discs, which play the planet's history and (to their surprise) allow their users to travel into the past through the atavachron, a time machine, into the periods each was studying on disc. The crew travels unprepared, McCoy and Spock find themselves locked in a frozen ice age 5,000 years ago, where Spock reverts to the barbaric age of the Vulcans. He becomes very easily agitated, and is intensely attracted to the political prisoner Zarabeth (Mariette Hartley), who enjoys getting company but tells them return is impossible. Kirk arrives in a Cromwellian period, where he's arrested and suspected of witchcraft. He soon realizes the magistrate must be a time traveler like him, and ...
Did You Know?
This is the only episode of TOS not to feature any scenes set aboard the Enterprise. See more
When Kirk is walking and interacting in his timeline, there is no question or reaction to his uniform or appearance which is out of place in the time period. See more
You've been dishonest with me, Spock, and that is also something new for you.
Special Enhanced version Digitally Remastered with new exterior shots and remade opening theme song See more