arrives at Omega 4 and finds its sister starship Exeter
in orbit and non-response. Kirk takes a landing part of himself, McCoy, Spock, and Galloway over but all they find are empty uniforms filled with handfuls of white crystal. The ship is deserted but when they check the medical log they find a warning from the ship’s medical officer. He recorded that a disease was brought up by the landing party while the captain, Ron Tracey, stayed on the planet. The doctor tells them that if they get down to the planet they’re safe. McCoy realizes that the handfuls of crystals are all that remain of the crew after all of the liquid in their bodies evaporated.
If you've come aboard this ship... you're dead men. Don't go back to your own ship. You have one chance. Get down there. Get down there fast. Captain Tracey is... arrgh!
The landing party beams directly to the surface where they interrupt an execution held by the locals, the Asiatic Kohms. The Kohms are executing a man and a woman, who are primitive Yangs. Tracey arrives and calls off the execution, as he clearly has some authority with the Kohms, who recognize phasers. The Yangs are locked up while Tracey explains how he survived the disease and that they are all trapped on the planet, immune as long as they remain there.
You'll stay alive only as long as you stay here. None of us will ever leave this planet.
While Spock and Galloway go out to scout the area, Kirk begins to wonder if Tracey has violated the Prime Directive. McCoy determines that the disease is the result of biological warfare that took place in the distant past, similar to what occurred on Earth. Spock returns with an injured Galloway and reports that as Tracey said, the Yangs are savages and massing for an attack on the Kohms. However, he also reports that he found empty power packs indicating that Tracey used his phaser to aid the Kohms against the Yangs. Tracey arrives and takes them prisoner. When Galloway goes for his phaser, Tracey kills him.
Tracey puts McCoy to work trying to distill the immunity factor, which he tells Kirk causes the locals to live for over a thousand years. Tracey plans to bargain for a starship and then sell it to the highest bidder. Kirk breaks free but Tracey quickly subdues him, then throws him in a cell with the Yangs. The male Yang attacks Kirk until Spock knocks out his mate, buying Kirk time to try and get the cell bars open. When Kirk mentions the word “freedom,” the male Yang speaks for the first time and clearly has some intelligence. He considers “freedom” a holy word, and Kirk uses it to convince him to help get the bars out of the window. After they succeed, the Yangs knock him out and escape.
Don't they ever rest?
Not that I have observed, Captain. Of course, should they wish to do so,
one could always rest while the other keeps you occupied.
Thank you, Spock.
Kirk wakes up and finds a key, and he and Spock sneak back to McCoy’s makeshift laboratory. There the doctor reveals that they all gained a natural immunity a few hours after landing and can leave the planet any time. Further, the natives are long-lived because they evolved that way and there’s no “fountain of youth” to be distilled. Spock tries to rig a makeshift communicator but a weary Tracey arrives and disintegrates it with his phaser, injuring Spock. Tracey has exhausted his other phaser power packs trying to hold off the Yangs but they have still defeated the Kohms. He takes Kirk outside to call up to the Enterprise
to signal for more phasers. Kirk does so but then they fight briefly before Kirk escapes. Tracey hunts him down but his phaser is drained completely so he grabs an axe and they fight. They’re interrupted when the Yangs arrive to take them all prisoner.
You'll fight, won't you?
The Yangs hold a victory celebration in the Kohm meeting place and the male Yang, Cloud William, declares victory. He has their banner brought in and it’s… the American Flag. Kirk and the others realize this planet is a parallel world to Earth, with the Yangs = Yankees and Kohms = Communists. They fought their cold war on this world but the Yangs lost and became primitives living off the land.
Yangs? Yanks? Spock? Yankees!
Kirk recognizes the Yangs’ holy words as the Declaration of Independence and tries to gain their trust. Tracey turns the Yangs against him by claiming Spock is the evil one resembling the Devil in their Bible, and that he has no heart. Cloud William demands that Kirk recite the most holy words but the captain doesn’t recognize them although they sound familiar. The Yangs are almost convinced, but Kirk asks for a trial by combat citing that good shall always beat evil.
Spock, I've found that evil usually triumphs unless good is very, very careful.
Kirk and Tracey are tied at the wrist and left to fight for a knife. As they do so, Spock manages to entrance the female Yang, Sirah, and get her to signal the Enterprise
for a security team. Kirk wins just as Sulu beams down with a security detail. They take Tracey prisoner while Kirk confronts Cloud William and reveals that the holy words are the U.S. Constitution. Kirk tells the Yangs that they must apply the words of freedom and equality to all people, even the Yangs, then leaves them to resolve their destiny and find their own path.
Gentlemen, the fighting is over here. I suggest we leave them to discover their history and their liberty.