"The Hijacked Planet"
The Enterprise is sent to the planet Styra, whose population is in danger due to eruptions from it's primary star. While proceeding at maximum speed to the planet, Scotty is enjoying a game of "Zap Ball" with a lovely young redheaded crewmember. He wins, and gets his reward (a kiss on the forehead) just as Spock arrives. Mr. Spock asks Scotty why he is not at his post on the bridge. Mr. Scott replies that he got Lieutenant Sulu to fill in for him. Spock reminds Scotty that unauthorized exchange of duties is specifically forbidden under "article 118" of general orders, and tells him that an emergency session has been called. The two travel to the briefing room, where Kirk and McCoy wait for them.
The spaceship turns out to be a little emergency craft - not a space cruiser. Spock puts on a spacesuit and crosses over to the apparently abandoned craft. (No mention of why the transporter was not used) He finds a lovely blonde woman lying on the floor in the interior of the craft. She is alive, and trying to talk in her unconscious state, saying "Calling any ship in space sector 18-J! Emergency! Out of fuel! All supplies gone!" over and over. Spock puts the woman in another space suit and carries her back to the Enterprise, where she is examined by Doctor McCoy. Kirk mentions to McCoy that he has seen her someplace before.
The Enterprise is attacked by a small craft, which fires a "super flare" at the ship. The flare disables the video circuits, and by the time the crew can react, the small ship is flying away from the Enterprise at top speed. An alert sounds - and Kirk and Spock discover that the vault which held the Styran recordings is empty. They also find that Allura is missing. Spock tells Kirk that he had realized that Allura was after the sphere, and that her "shipwreck" in space had been phony. He had set a trap in the space hatch to catch her. Kirk, however, discovers that she has blown open the outer door to the hatch and escaped along with the Styran sphere to the small ship which attacked the Enterprise.
The Enterprise is shortly contacted by the perpetrator of the crime (Allura's partner Anzar), who appears on the main viewscreen with Allura in the background. He demands 100 million credits be deposited into his account within 24 hours, or he will destroy Styra. Using a scrambling device, the Enterprise relays the message to the Federation Council. The Council decides to take whatever measures are necessary - except paying blackmail - in order to save the planet Styra. The decision is kept secret from Anzar so that Kirk will have freedom to act.
Kirk tells Anzar that his basic terms are acceptable, but that details need to be worked out. Anzar agrees to meet Kirk "in the Great Cave of Lurota" at noon the following day. Kirk and Spock beam down to the cave. Anzar is waiting for them, sitting behind a huge futuristic-looking desk. He tells Kirk that he will not negotiate, and that he will take no less than 100 million credits in "precious jewels and the rarest of metals". Kirk tells Anzar that he never meant to negotiate, and that the best he can hope for is for his life to be spared! Kirk draws his phaser. The criminal has several henchmen posted around the cave, and they close in on Kirk and Spock. The pair flees deeper into the cave and arrive at an intersection. They split up - Kirk taking the left tunnel, and Spock the right, with the gunmen right on their heels. Spock runs into a dead end, and is captured.
Spock tells Anzar that he has a plan to help him get his money. He suggests that the wealthiest citizens of Styra, who are stored on tape, will pay hansomely to protect their world. Spock offers to steal the portable transmutation device stored on the Enterprise in order to restore the wealthy Styrans. He sneaks aboard the Enterprise and does so, knocking one guard unconscious in the process. (With a nasty blow to the back of the head with his phaser) He returns to the planet surface with the device. Anzar lets Spock activate the device, but instead of wealthy Styrans - Kirk pops out, followed by Scotty and several security guards!
"Shame on you, Anzar! Didn't you ever read about the Trojan Horse?" Spock asks. The Enterprise crew quickly overcomes the gunmen, and they surrender. Anzar, however, does not. He holds a gun to the sphere that contains the population of the planet Styra and threatens to destroy it. He tells the Enterprise crew to work the controls of the device, and restore the wealthy Styrans. Scotty takes the controls, and activates the device. The terrier dog that Kirk had restored at the beginning of the voyage appears, immediately jumps on Anzar, and viciously attacks him. He loses his gun, and is taken prisoner - while he rants and raves about "schemes beyond the grasp of your little brains".
Spock says good-bye to Allura, calling her "an uncommonly lovely woman", and tells her that she made it very easy for him to pretend that he loved her. Kirk asks Scotty how he thought to bring the tape of the dog with him. "I didn't do it on purpose!" Scott says. He had taped the dog earlier because he know how the captain felt about pets on the ship, and was worried that Kirk "would have him shot or something!". "Quite right, Mr. Scott!" Says Kirk. "Actually, I was just thinking of having him served at the officer's mess!"