"Sceptre of the Sun"
While the Enterprise is proceeding through Sector Vega toward a rendezvous with Space Ambassador Mason at Starbase 10, Mr. Sulu detects a large nebulous mass approaching the ship. The cloud takes the form of a huge man wearing ancient Arabian clothing, and it catches the Enterprise in it's grip. "A genie!" shouts Mr. Sulu, "we've been caught by an honest to space genie!". "Impossible!" Mr. Spock replies. "My sensors indicate nothing out there. What you see is an illusion!". Suddenly, a strange mist arises on the bridge, and the Captain, Mr. Spock, Dr. McCoy, and Mr. Scott disappear.
The four men materialize in the throne room of a huge castle. They are welcomed by a bald man wearing ornate purple robes. He introduces himself as Chang, and tells the Enterprise crew that he has brought them there by sorcery. Scotty approaches the man. "I don'a care if yer name's Chang or me Great Aunt Tillie!", Scotty says, threatening him. Chang uses special powers to immobilize the engineer, and then tells Kirk the reason he has summoned them to his planet.
At the foot of a mountain many miles from his castle lies a mystic device called the "Sceptre of the Sun", which possesses "powers unmatched anywhere in the universe". Chang wishes to use the power of the Sceptre to counteract a spell, cast by a rival sorcerer named Xandu. The two sorcerer's kingdoms are at war, and Xandu has caused a huge, enchanted flaming sword to hang in the air over Chang's city. Any hostile action on the part of Chang's people would cause the sword to destroy them! Spock asks Chang why he needs them to get the Sceptre for him, as his powers are so much greater than theirs. Chang refuses to answer, and threatens to destroy the Enterprise if they don't do as he wishes. Kirk agrees.
Chang introduces Marla, a lovely young woman who will be their guide into the mountains, and wishes them luck. "If anything happens to the Enterprise in the interim, the whole universe will be too small to hide you!" says Kirk.
The four crew members set off in search of the Sceptre of the Sun, with Marla leading the way. On the way, Kirk "senses" something strange in the air, and questions Spock about it. "I 'sense' nothing, Captain", Spock says, "But I will admit that things are uncommonly still in this area. Almost too quiet!". Just then, the cliff walls around them begin to move. The stone shifts and molds itself, taking the form of two huge rock giants! The enormous creatures use clubs to try and smash the travellers. In a desperate attempt to save their lives, Kirk and Spock run in between the two giants. The creatures swing their clubs at the pair, but hit each other instead, destroying themselves.
As the sun goes down, the group sets up camp for the night. Kirk questions Marla about Chang and the source of his powers. "He came amongst us unawares - down from the dark mountains to the north!" she says. "We had been a quiet, peaceful people, but Chang changed all that! His vast mystic powers twisted us - bent us to his will! In a short while, he had made himself our king and there was nobody strong enough to stop him!". At that moment, the camp is attacked by a band of primitive looking men carrying swords. The group fights valiantly, but Kirk is taken captive and the men threaten to kill him unless the others surrender.
Finally, resigned to defeat, we constructed a great spaceship and fled Earth in search of a peaceful world! For many years, we drifted through space in suspended animation until our robot sensors discovered this planet, a quiet, peaceful world still in its industrial infancy. Upon reviving, we landed in a secluded spot and began dismantling our rocket - for this world was to be our home from now on".
"It was easy for us to mingle with the simple people we discovered here", Brand continues. "Life was perfect, all anyone could hope for. Anyone, that is, save Chang". Brand tells them how a bored Chang had left their group and returned several months later, having enslaved a band of the planet's inhabitants. "But this was not the same Chang, for something had happened to him on his trip through the mountains, something strange... sinister". Under threat of Chang's new powers, Brand's men had been forced to serve Chang up till this time.
Brand tells Kirk that his spy in Chang's guard had told him of their quest for the sceptre, and that he and his men wish to come along. Using the power of the sceptre, they hope to liberate their world from Chang. As they are outnumbered, Kirk has no choice but to let Brand and his men accompany them. The group travels mile after mile, until they come to a small temple, carved in a cliff wall, that contains the Sceptre of the Sun. As they approach it, a huge guardian robot attacks them. Kirk takes the sceptre and tries to use it against the robot, but nothing happens. Spock tells Kirk to distract the robot, while he carries out a plan he has devised. "Your mother wore an asteroid wig!" Kirk shouts at the robot. "And ye're father flew a space scow!" Scotty adds. With the robot distracted, Spock climbs up on a ledge and jumps over onto the robot. He opens a panel, rips out several wires, and the robot comes crashing to the ground.
Kirk asks Spock why the sceptre did not work when he tried to use it. "None of what we have experienced is the least bit logical!" Spock says. "Why, for example, would a robot - a product of science, guard a magical sceptre?". The Enterprise crew members, Marla, and Brand's men travel back to Chang's palace to find answers. When they arrive, they overpower the palace guards and storm the throne room. They find Chang at the controls of a huge computer. Brand rushes at Chang, and is quickly turned into a large toad. Chang explains to Kirk that his machine is pulling the Enterprise down to the planet! "Once the vast resources of that galaxy-spanning craft are under my control, nothing in the universe will be able to stand against me!" he rants.
As Spock approaches him, Chang uses his power to create a large gorilla-like alien being. Spock is undeterred, and walks right through the creature! "Everything we've seen and experienced on our quest was only illusions!" he says. "Chang made us believe it all existed, when, in truth, it was all in our minds!". "It was all a ruse", Spock continues, "a scheme to distract us, the command officers of the Enterprise, long enough for Chang to take over the ship, and with his illusionary powers, it would have been simple indeed!". Chang orders more of his guards to attack the party, and in the confusion, he escapes. Kirk follow him to the top of a tower nearby. The two struggle, and Kirk loses his phaser. As Chang is about to kill the Captain, a bolt of lightning strikes his upraised sword, and he is killed.
Kirk and Spock examine Chang's tractor beam device, trying to find a way to shut it down, but are unsuccessful. Kirk contacts the Enterprise and orders it to fire a full-power phaser blast at the palace in 90 seconds, giving the landing party time to escape with Brand and his men. The palace is destroyed, and the tractor beam releases the ship. Later, as the Enterprise "arcs off towards the velvet void of space", Kirk discusses the events with Mr. Spock and Dr. McCoy. "Well Jim, Brand has his peaceful planet again!", says the Doctor. "I only hope there are no other Changs around waiting to strike!". "The irony is that Chang with all his genius had the potential to construct a space ship on his own" Spock says, "If only he had the patience to wait until he could do so, he might well have conquered the galaxies!". "I know Spock," replies Kirk. "But Chang's secret died with him, and for all our sakes, let's hope they stay that way!".