Star Trek: Episodes 77, 78 & 79 - The Savage Curtain/All Our Yest

The Savage Curtain Stardate:5906.4 Ultimate battle of good and evil? While surveying a planet composed of lava, the crew of the Enterprise is startled when Abraham Lincoln requests permission to board! Intrigued, Kirk affords him due honours; then he and Spock follow Lincoln to the planet where they meet Yarnek, a rock creature. Yarnek pits the "good" men against an equal number of tyrants, representing "evil" , so his race can learn which is stronger. The stakes are high: if Kirk loses, Yarnek will destroy the Enterprise. All Our Yesterday's Stardate: 5943.7 Kirk, Spock and McCoy beam down to Sarpeidon to rescue inhabitants before its sun explodes. But they arrive to find that only the planet's libarian's, who has helped all the others to safety via a time machine. When Kirk acidentally enters the past, Spock and McCoy attempt a rescue, emerging in a bitter ice age! Spock, now a throwback to earlier Vulcan times, falls in love with a beautiful woman and has no intention of returning to Kirk or the Enterprise! Turnabout Intruder Stardate: 5928.5 The Enterprise recieves a distress call from Camus II , where they find all but two inhabitants dead from radiation. One survivor, Janice Lester, is an old friend of Captain Kirk's. But now she despises him and uses an alien technique to exchange bodies with him. When Kirk/janice tries to explain things, Spock, Scotty and McCoy are accused of mutiny and Janice/Kirk calls for the death penality! This is the only time Kirk was played by another actor - Sandra Smith as Kirk/Janice.