Star Trek: The Apple

On stardate 3715.3, the starship USS Enterprise arrives at Gamma Trianguli VI, a planet that appears to be a tropical paradise with very rich natural resources. Captain James T. Kirk, Dr. Leonard McCoy, Ensign Pavel Chekov, and Mr. Spock, along with five other survey personnel, beam down to the surface to have a look and to make contact with the natives.
They discover a world of poison dart-shooting plants, unstable explosive rocks, and bizarre lightning storms that appear out of cloudless skies. One of the crewmen is shot by a plant and is killed, and then Spock is hit by another plant's darts when he steps to block them from hitting the Captain. Spock is stunned, and McCoy rushes over to assist, injecting him with Masiform-D serum to counteract the poison. Spock is more resilient to the poison and later recovers on his own.
Realizing there is too much danger, Kirk orders an immediate beam-out, however Mr. Scott reports that the ship's power systems are being drained by an unknown energy field emanating from the planet - they're losing potency in the anti-matter. The Enterprise's transporters don't have enough power to beam anyone back. As if this weren't enough, Spock reports that someone is hiding in the bushes, watching them.
A few minutes later, the sky clouds up and a bolt of lightning snakes down and hits another security man, killing him. Shortly thereafter, the third security man calls in on his communicator. He's near the village and says it's "primitive, strictly tribal," but that there's something else of great interest. His communicator fails and he runs back to the landing party to report, but trips over an explosive rock and is killed.
Spock notices they are being watched again. Kirk arranges to decoy and ambush their "observer", finding it to be a shy and frightened primitive humanoid who wears glitter and colorful paints on his skin. Kirk promises not to hurt the curious man and holds him for questioning. The man calms down and identifies himself as Akuta, chief of the people known as the "Feeders of Vaal". Spock notices that Akuta appears to be in some kind of communication with someone, and points out the small antennae on Akuta's head. Akuta explains that those are his "ears for Vaal", enabling him to interpret Vaal's commands for the people, and that he is "the eyes and the ears of Vaal", who is their god.
Meanwhile, Mr. Scott calls down to inform Kirk that the Enterprise is being pulled down from orbit around the planet by some kind of tractor beam and is unable to break away. Kirk asks Akuta about "Vaal", and requests to be taken to meet him. Akuta agrees and leads the landing team to a large stone dragon head carved into the side of hill. Akuta points to the structure and indicates that it is Vaal.
The dragon's mouth, with steps cut into a tongue, appears as a kind of doorway. Spock's tricorder indicates that it leads underground. The structure is also protected by a powerful force field. The temple appears to be some type of sophisticated computer, possibly built by an ancient civilization, with a rudimentary artificial intelligence, a thirty-foot force field, and emanating great power. Spock also concludes that it may be the source of the energy draining field that is affecting the Enterprise.
Akuta says Vaal is "sleeping", but will awake "hungry" and might speak to the landing party at that time. He then leads the party to meet his people. They appear as young men and women, but all have a curious, childlike mentality. Kirk points out that the tribe doesn't seem to have any children and asks Akuta why. Akuta doesn't know what a child is, saying that Vaal has forbidden love and copulation, and provides them with "replacements" as they are needed. McCoy scans the tribe and is shocked when he discovers they are ageless and all in perfect health. The party later observes them as they perform a ritualistic "feeding" of Vaal, carrying loads of the explosive rocks down into the underground tunnel. The picture is now clear; the people live only to service Vaal, to dance, and to gather food. They don't even do their own agriculture, since Vaal controls the environment right down to "putting the fruit on the trees".
Mr. Spock observes the symbiosis between the Feeders and Vaal as an "excellent example of reciprocity", but McCoy vehemently disagrees and says the Feeders are not really alive, but stagnating, all their needs and wants provided for by a "hunk of tin". He insists that because they are humanoid, certain "universal standards" apply to them, "the right of humanoids to a free and unchained environment, the right to have conditions which permit growth." Kirk says it's more important to get the Enterprise out of danger.
Throughout their time on the planet, Chekov and Yeoman Martha Landon (Celeste Yarnall) have been showing interest in one another, and during a lull in the action slip away to be alone together. A tribal couple observe the pair and try to imitate their kissing. Vaal is instantly aware of this and radios instructions to Akuta, telling him to gather his people and kill the strangers who have trespassed here. Akuta rounds some of his men and instructs them to kill the landing party by bashing their skulls with clubs.
The landing party goes to Vaal to investigate the structure. Vaal defends itself by striking Spock with a lightning bolt. The Feeders then attack, surrounding the landing party and killing a crewman. The landing party fights them off and then detains the Feeders.
Under Scott's command, the Enterprise crew have been switching all systems over to generate a thrust and now, with 15 minutes left, begins its effort to break free. All seems to be working, then the effort fails. Scott says they gained maybe an hour, but they blew nearly every system doing it. Kirk "fires" Scott. Just then, Vaal, perhaps weakened by the starship's efforts, calls for the villagers. Chekov tells the people to stay in the hut, preventing them from feeding Vaal.
Kirk orders the ship's weapons to target the structure and fire on the forcefield, intending to force Vaal to use its reserves. The ship blasts the dragon head with phasers and Vaal uses the reserves to reinforce the forcefield, but cannot hold out: Vaal's glowing eyes go dark; Kirk orders ceasefire; Vaal lights again only briefly.
Scott reports that the tractor beam is no longer pulling the ship, potency is returning to the anti-matter pods, and repairs are under way, so Kirk rehires Scott and orders a scientific and engineering detail down to investigate Vaal's remains.
Akuta and his people are devastated, but are told by Kirk that they are finally free and will soon discover work, birth, death, and the normal everyday ways of life.
Back aboard ship, Spock compares what the Captain has done to giving the primitive people the equivalent of the apple of knowledge and driving them from their Garden of Eden, but Kirk maintains that Spock's resemblance to the Devil is much more apparent than his own.