'Errand of Mercy' is a first season episode of original Trek. It is an important one, as it introduces one of the classic Trek villains-later allies- the Klingons. As the show starts, Kirk and Spock are discussing a report that's been received that negotiations between the Federation and Klingon Empire over a disputed region of space are breaking down. The Enterprise has been ordered to proceed to Organia, a neutral planet of great strategic importance in the contested territory. It is assumed that the Klingons will attempt to conquer the planet in order to gain an advantage over the Federation, and Kirk's instructions are to do whatever necessary to prevent this from happening. Spock gives him a rundown of what they know about the Organians: they are a peaceful, friendly people with a relatively primitive culture. As they discuss this, the deflector screens go up, and Sulu informs them that a ship is approaching. It is Klingon, and fires on them, causing minimal damage. Kirk orders return fire, which destroys the Klingon vessel. Directly following this, Uhura receives another message from Star Fleet- Code One. Upon hearing this, Kirk remarks to Spock, "Well, there it is...war. We didn't want it, but we've got it." To which Spock replies,"Curious how often you humans manage to obtain that which you do not want." Their mission to Organia has just become much more important, and they proceed there with all haste.
Upon arrival, Kirk leaves Sulu in command of the Enterprise, telling him that if a Klingon fleet should arrive, his duty is to get the ship to safety and warn Star Fleet. He and Spock then beam down to the planet, which seems to be at about a Medieval level of development. They are met by a man named Ayelborne, who welcomes them to Organia. Kirk introduces himself and asks to speak to someone in authority. Ayelborne says that they have no authorities, but that he is the chairman of the council of elders, and tyhat Kirk can talk to them if he wants. While Kirk goes to the council room, Spock heads off to study the local populace and their culture.
Addressing the council, Kirk warns them about the coming Klingon invasion, and offers the resources of the Federation so that they can defend themselves. Ayleborne remarks that Kirk seems to be giving them a choice: deal with the Federation or deal with their enemies. Kirk points out that the Klingons will offer no choice; the Empire is a military dictatorship which will simply seize their planet and enslave their people. The councilmen seem remarkably unconcerned about this... they maintain that they have nothing that anyone would want, and that they are in no danger. Understandably confused by their refusal to entertain the possibility that the Klingons will harm them, Kirk forcefully urges them to reconsider. The council asks for time to discuss his concerns, and while they do so, Spock returns from his perusal of the town. He tells Kirk that Organian society is not merely pre-industrial as they had assumed, but is completely stagnant- there is no sign of any progress having been made in thousands of years. As they mull this over, the council announces that their opinion remains the same- they don't want any help. Ayleborne thanks them for their concern, and advises them to return to their ship so that they won't be in any danger themselves. Kirk tries again, this time including an offer to help them advance their arrested culture with technology and medical science. They aren't interested.
Just then, Sulu contacts them to say that a bunch of Klingon ships have turned up, and have opened fire on the Enterprise. With the shields up, he can't beam them back aboard, and Kirk orders him to withdraw, go to warn Star Fleet, and return with backup. Sulu obeys, and soon afterwards, armed Klingons start materializing on Organia. Still insisting that they have nothing to worry about as a Klingon occupation army takes over, the councilmen provide Kirk and Spock with clothing so that they won't be recognized as Star Fleet officers.
Then Spock makes a disturbing discovery: while they were changing, the Organians stole their phasers. Admirably restrained under the circumstances, Kirk politely asks Ayleborne to give them back, who just as politely refuses, saying that, if they had weapons, Kirk and Spock might be tempted to use violence. Ironically, as he says this the Klingons march into the council chamber, having taken over the planet with literally no effort.
Their leader is Kor, and he's not happy. He was hoping for a good fight, and the pacifist Organians neglected to provide him with one. And as he announces that he has declared himself Military Governor of Organia, the councilmen simply sit there, smiling and politely welcoming him. Kor turns his attention to Kirk, demanding to know who he is. Ayleborne says that he is Barona, a leading citizen. Kor wants to know why he's not grinning like an idiot like everyone else, then without waiting for a response turns to interrogate Spock. Spock says that he is a merchant, but Kor is suspicious that, Vulcan being a member of the Federation, he might be a spy. He orders Spock taken for interrogation and Kirk automatically protests, to Kor's enjoyment. He comments that there seems to be a "ram among the sheep". Speaking of whom, Kor tells the council that they are now part of the Klingon Empire and subject to its rules and regulations, the slightest infraction of which is punishable by death. Ayleborne tells him calmly that they will obey his commands. Disgusted by their meek compliance, and amused by Kirk's thinly-veiled hostility, he appoints Kirk liaison between himself and the Organians.
As Spock is led away for interrogation, Kor takes Kirk to his office to impart the new legislation for the Organian people. It's standard evil dictator fare: no public assemblies, control of the press, surveillance and patrols of neighbourhoods, a list of capital crimes against the state... the usual. As he is reciting this cornucopia of delights, Kor's aide brings Spock in, saying that he is who he claimed to be- a merchant. Kor accepts this, because they used their "mind sifter" on Spock. It is, as he explains to Kirk, a device which can read the thoughts and memories of those subjected to it. A useful tool and, as he adds menacingly, a weapon which, when used at full power, empties the mind and leaves the subject a mental vegetable. Kor tells Spock that he is free to go, but will be watched. Not wanting Kirk to feel left out, he tells him that if anyone breaks the rules, he- Kirk- will be held responsible and be killed. Kor really missed his calling as a motivational speaker.
Later as they walk through town, Spock describes the mind sifter to Kirk, saying that it is extremely strong, but that he beat it using a mental defense technique. He then has to restrain his captain from using a physical offense technique to beat a Klingon soldier who pushes the already cranky Kirk. As Spock points out, they can't afford to draw attention to themselves. Calming, Kirk agrees, and says that they must find a way to complete their mission. Spock acknowledges this, but says that the Organians will be of no help to them. Kirk disagrees- he thinks that even the meek Organians will get sick of tyranny, and may just need to be shown that they can fight back against their oppressors. To this end, the two of them make a nighttime raid on the Klingon's munition stockpile, blowing it up.
Far from being inspired, however, the councilmen are horrified by Kirk and Spock's use of violence, deploring their wanton destruction of the Klingon's property. Exasperated, Kirk tries to convince them that they can push back against the Klingons... maybe not defeat them, but inconvenience them and keep them off balance. Spock points out that the Federation will eventually make it there with troops- they need only hold out until then. The Organians are unmoved, and Kirk loses his temper, accusing them of not having enough courage to fight for their freedom or protect their loved ones.
Unfortunately, what they don't know is that Kor has the council chamber under surveillance, and is listening with interest to this little drama playing out. When he's heard enough, Kor leads some of his guards to the chamber and arrests Kirk and Spock. Far from being angry with them, his admiration for them is obvious, as is his disdain for the Organians whom he sneers at for their cowardice. Of course, Barona and Spock must be executed- it's nothing personal, just business- after Barona does a stint in the mind shifter to see who he really is. Then, because he hasn't done enough, Ayleborne helpfully blabs that Barona is actually Captain James T. Kirk of the star ship Enterprise.
Kor is tickled pink... well, figuratively... and not just because he has the captain of the Federation's flagship in his grasp. Kirk has a reputation for being a fierce and clever warrior, and Kor had always hoped to meet him in battle. Now of course, he'll have to content himself with merely frying his brain and executing him. Oh, well- not every dream can come true.
Happy as he is to have Kirk, Kor is disgusted that the Organians are so lacking in honour that they would betray him like that. In this, he and Kirk are perfectly united, Kirk contemptuously telling Ayleborne that though he is used to the threat of death, he has no desire to die for the likes of them. Kor takes then Kirk to his office for a private conversation. Having won, Kor is feeling expansive, telling Kirk that he admires the Federation- that it has much in common with the Klingon Empire. Kirk snaps back that they're nothing alike: they have democracy and freedom, while the Empire conquers and forces others to live under their despotic rule. Kor brushes this aside as a "minor ideological difference", saying that it is in nature that they are similar: they are predators, hunters and killers, which is what makes them great. Out of respect for a fellow soldier, he offers Kirk the opportunity to provide him with the information he wants about Star Fleet's plans so that he won't have to destroy his brain with the mind sifter. Of course Kirk refuses, and Kor tells him that if he doesn't cooperate, while he is having his mind turned to mush during interrogation, Spock will be dissected to find out how he beat their machine. He then makes the classic blunder of giving Kirk several hours to decide, throwing him and Spock into a prison cell.
While they discuss the situation they find themselves in, Kirk and Spock hear their cell door being opened, and assuming it's a guard, get ready to jump him. To their surprise, it is Ayleborne: he's come to let them out because Kor intends to harm them. He takes them back to the council chamber. Spock is wondering how Ayleborne managed to get passed the guards, while Kirk is just thoroughly confused by the Organian's contradictory behaviour. He points out that Ayleborne turned them in, then got them out, and sarcastically asks if now he's waiting for the Klingons to post a reward for their capture so that he can turn them in again and collect it.
Unfortunately, Kor is not going to offer a reward. When he finds out that Kirk and Spock have mysteriously vanished from their cell, he realizes that they must have had outside help. In retaliation, he has 200 Organian civilians rounded up in the town square. Then, broadcasting the event, he has them all disintegrated by phaser fire. He lets it be known that every two hours two hundred more will be executed until Kirk and Spock are turned in. Kirk has had it with the council... they sit around smiling and tut-tutting about his violent tendencies while their people are being murdered in the street. Kirk says that he will allow no more people to die on his account, and demands their phasers back. At first Ayleborne refuses to tell him where they are, but when Kirk threatens to give him an up-close look at his violent tendencies, relents and hands over the phasers. Now armed, Kirk tells the council that he and Spock are going to take on the Klingons- and probably get killed- in an attempt to show them that some things are worth dying for. Ayleborne points out that there are only two of them against an army: don't they realize how futile their actions are? Kirk just gazes at him witheringly, then he and Spock head out the door.
The two of them manage to shoot, punch, and nerve-pinch their way to Kor's office, where he informs them that a Federation fleet is approaching the planet, and the Klingon fleet is preparing to meet them in battle. He appears to relish the thought. He says that the Klingons will win, because they are more ruthless and fight as a unit, pointing out that in the Empire, no one is above suspicion- not even leaders like him, who are under constant surveillance. Realizing that their presence will be known, Kirk and Spock position themselves defensively as Kor's guards burst in. Kor yells at them to shoot, but suddenly they all drop their phasers, yelping in pain. It feels as though all the weapons have become super hot.When they try to fight physically, they find out that they can't touch each other for the same reason- it feels like their skin is burning when they attempt it. It turns out that the same thing is happening on all the Star Fleet and Klingon ships- no one cane touch their instrument or weapon panels. As they try to figure out what's going on, Ayleborne and one of the other councilmen wander in. They apologize for interfering, but say that they cannot allow violence to occur, and so all instruments of violence now radiate a temperature of 350 degrees. Ayleborne says that he is going to put a stop to their "insane war", and unless they agree to an immediate ceasefire, both of their fleets will be completely immobilized.
Kirk and Kor find themselves once again united in their anger at the Organians. Kor says that they have no right to interfere with what goes on in space. Kirk argues that Star Fleet has legitimate grievances with the Klingons, who have invaded Federation territories, killed their citizens, and have declared their intention to conquer half of the galaxy. He angrily points out that the Organians should be on their side- Kor just had 200 of their people killed. Ayleborne says that no one actually died... that no one has died on Organia in thousands of years. Blinking a little at this, Kirk blusters that, even if they do have some special powers, they have no right to dictate to the Federation- or, Kor chimes in, the Empire- how to conduct their disputes. Ayleborne asks Kirk if he is arguing for the right to wage war, to kill billions of people, and to destroy life on a planetary scale... is that what he's defending? Somewhat deflated, Kirk says, well, of course no one wants war, but that people have the right to handle their own affairs and work them out themselves. Ayleborne counters that letting them work it out themselves would result in countless needless deaths, and that the Federation and Klingon Empire will one day be allies. Kor rejects this as utter nonsense. The councilmen say that, though they don't wish to be inhospitable, they must ask all of them to leave the planet- all this violent emotion is extremely painful to beings like them.
Kirk questions what they mean by this, and Ayleborne explains that once, long ago, the Organians were a humanoid people, but have since evolved beyond the need for physical bodies. They merely adopted these present forms for the sake of their visitors. They then turn back into their natural energy forms and disappear. Spock of course finds all of this fascinating, speculating that the town and buildings are there only to provide visitors with familiar reference points. He says that the Organians are as far above them as they are above the amoeba. A chastened Kirk tells Kor that they might as well forget about the war: the Organians aren't going to let them fight. Kor regrets this- he says that it would have been "glorious".
Back on board the Enterprise, Spock remarks that Kirk has been pretty quiet since their return. Kirk admits that he's embarrassed: he was actually arguing for a war he didn't want. Spock tells him that it took the Organians millions of years to become what they are, so it's illogical to be embarrassed that they have not reached that level themselves. War averted- at least for now- the Enterprise heads off for their next adventure.