[[caption-width-right:350:If Charlie makes this face, you are ''unfathomable'' levels of screwed.]]

-->'''Charlie:''' Do you know about being with somebody? Wanting to be? [[StalkerWithACrush If I had the whole universe, I'd give it to you, Janice. When I see you, I feel like I'm hungry all over. Do you know how that feels?]]

The Enterprise takes on a passenger, [[BlatantLies being that they are commonly in the habit of ferrying civilians]]. The boy is Charlie, an orphan with a MysteriousPast and [[NoSocialSkills really bad social skills.]] The people dropping him off seem in quite a hurry to leave.

Charlie becomes infatuated with Yeoman Rand, [[StalkerWithACrush stalking her]] and delivering presents she doesn't want. In the rec room we get to see Spock and Uhura make [[TheCastShowoff music]] together, which annoys Charlie because it distracts everyone (and especially Yeoman Rand) from him.

The ship Charlie arrived on blows up mid-transmission, with Charlie making a snide remark. Everyone is somewhat concerned, especially as odd things continue to happen upon the ship. For instance, Charlie loses chess and causes the chess pieces to melt. Nobody connects this to him (yet). Kirk is given the responsibility of talking to the boy and attempting to explain how to be normal.

Which he does by teaching him to [[ShirtlessScene wrestle]]. (Obviously.) When Kirk’s training partner laughs at Charlie, Charlie makes him disappear. Kirk is upset and orders him to his quarters, where he goes after making several threats. Charlie goes on a rampage when Kirk refuses bring him to the human colony he was planning on going to. The aliens that taught Charlie his powers appear to take him back, apologizing for the damage he's caused. He is brought back to live with them and the people that were attacked are [[ResetButton brought back to normal]].

* AbsenteeActor: Scotty and Sulu don't appear in this episode, although two words of the latter's dialog from "[[Recap/StarTrekS1E1TheManTrap The Man Trap]]" are dubbed in when Kirk calls the bridge from the gymnasium.
* AlasPoorVillain: Charlie doesn't want to go back with the Thasians, as they aren't physically real like Kirk or Rand. Kirk evens argues for a chance for Charlie to stay if he can be rehabilitated. But the Thasians point out they can't undo the talents they'd given Charlie to survive on their world. Charlie begs to stay... stay.... stay.........
* BigNo: Charlie screams it when a Thasian ship arrives to take him home to his kind.
* TheBlank: Charlie [[NightmareFuel erases several]] random crew members' faces while having a tantrum.
* CharacterizationMarchesOn: Spock is smiling throughout Uhura's performance serenading him, merrily strumming along on his Vulcan lyre without so much as a quip or a sarcastic comment when she's finished. This is unquestionably the most laid-back we ever see Spock (without mind-altering devices being at work), and rings ''very'' false for him - contrast Spock and Uhura interacting the previous week in "[[Recap/StarTrekS1E1TheManTrap The Man Trap]]".
** This was a case of ShipTease on the part of Creator/NichelleNichols, Creator/LeonardNimoy and the writing staff. When the show first started, they wanted to drop hints that Uhura and Spock would end up together. Nichols and Nimoy played it this way even into the third season (watch Spock whenever Uhura gets zapped or falls out of her chair). Of course, NBC couldn't allow it to be any more explicit than that, as interracial romance would have cost them the all-important southern affiliates. There's more WhatCouldHaveBeen in the recap for "[[Recap/StarTrekS3E10PlatosStepchildren Plato's Stepchildren]]".
* {{Chiaroscuro}}: In the gym when Kirk and Charlie are facing off, the lighting somehow changes mid-scene to make both Charlie and Kirk appear as though they are in a typical FilmNoir scene with venetian blinds. Also, their eye areas are highlighted to emphasize the drama and tension.
* CreatorCameo: Creator/GeneRoddenberry provides the voice of the Galley Chief amazed at the appearance of real turkeys.
* DeathGlare: Charlie has one using his powers. Kirk gives him one of his own after he breaks Spock's legs.
* DidYouJustFlipOffCthulhu: Kirk grabs the sociopathic man-child with superhuman powers and throws him out of his chair. Moral: Do ''not'' take the captain's chair!
* DisconnectedByDeath: The ''Antares''.
* DisproportionateRetribution: Charlie makes a crewmember in the gym disappear because he laughed at Charlie getting put on his ass by Kirk. A gaggle of anonymous crewmembers are [[BodyHorror rendered]] [[TheBlank faceless]] because they just happened to be laughing when Charlie stormed past. One female crewmember is turned into a lizard after expressing genuine concern for him. And Charlie wonders why nobody likes him.
* DownerEnding: Charlie only wanted to be liked and accepted by the crew. His temper and "talent" make it impossible but it's not his fault (entirely) since he'd been alone since age three.
* EarlyInstallmentWeirdness: The Antares crew's tan, ribbed-collar tunics
** Kirk & Co. work for the United Earth Space Probe Agency.
** The rank insignia on Kirk's green tunic are on his shoulders instead of around his wrists, where they would appear later in the series
* EldritchStarship: The Thasians' ship resembles a nebulous mobile cloud of glowing green gas (in the original version); in the Remastered episode, it is similar looking, but with some kind of lighted tubes inside the gas cloud. The Thasians themselves are noncorporeal aliens who appeared to the Enterprise crew as floating, ghostly green humanoid heads.
* ExplosiveInstrumentation: The communication console emits a shower of sparks and burns Uhura's hand. Justified in this case because it's Charlie using his powers to prevent communications with anyone outside the ship; Uhura states that there wouldn't normally be any reason for it to do that.
* {{Expy}}:
** Many have compared Charlie to Anthony Fremont from ''Series/TheTwilightZone'' episode "[[Literature/ItsAGoodLife It's A Good Life]]".
** Also to Valentine Smith from the novel ''Literature/StrangerInAStrangeLand''.
** Some may have noticed the title "Charlie X" and a connection to [[ComicBook/XMen a certain Charles Xavier]]. The debut of the comic book ''X-Men'' does predate this episode by three years but Professor X (who rarely if ever goes by "Charlie") is of course a mature man with telepathic (not telekinetic) powers that he only uses for the good of mankind. Also, at the time of this episode, the X-Men were one of the more obscure Marvel titles. It's most probable that any similarities were coincidental.
** Also might be an expy of Charlie Gordon, in ''Literature/FlowersForAlgernon'', as a young man unable to cope with the powers he has been given.
* GaussianGirl:
** Yeoman Rand gets the fuzzy treatment in all her close-ups (and not just the ones that are representing the infatuated Charlie's point of view).
** So, for some reason, does William Shatner.
* HisNameIs: The ''Antares'' tries to contact the ''Enterprise'' to warn them about Charlie (presumably after they felt they were a safe distance away), but Charlie destroys their ship, trying to pass it off as being a result of the ship being poorly built. Nobody buys it at this point.
* InstantCostumeChange: While [[BoldlyComing Kirk]] fumbles his way through [[TheTalk The Talk]] with Charlie, he is wearing his command gold tunic. When he responds to an urgent call from the bridge in the next scene, he's back in the green tunic. The most likely explanation is that Kirk had so many [[ShirtlessScene shirtless scenes]] they couldn't fit them all into the show.
* KilledMidSentence: The entire crew of the ''Antares''.
* MindRape: There's a bit where Charlie is making Spock recite poetry instead of say what he wants to say on the intercom. Charlie comments that [[PeoplePuppets he could make Spock spin around, dance or laugh]]. A couple of seasons later, [[ProductionForeshadowing the Platonians do just that]].
* MrFanservice: Kirk [[ShirtlessScene shirtless]]!
** [[PunctuatedForEmphasis And! In! Tights!]]
* NoSocialSkills: Charlie has insufferably poor social skills.
* PsychicPowers: Charlie can do lots of things, including transmogrification and making people involuntarily recite poetry.
** He can also reach into Yeoman Rand's head and discover her favorite perfume. Ew.
* PsychopathicManChild[=/=]TeensAreMonsters: Charlie, with his ability to make people vanish.
* RedShirt: The one guy in the gym that laughs at Charlie. Charlie starts his rampage by making him disappear. Interestingly, he's wearing a red dogi. Other crewmembers of all uniform colors suffer in some way or another for offenses both great and small.
* ResetButton: The Thasians undo everything Charlie did on the ''Enterprise'', [[SubvertedTrope but are unable to do anything]] for the crew of the ''Antares'', who were killed by a warp core breach (caused by Charlie) rather than merely being transformed or disappeared.
* ReplacementGoldfish: Rand attempts to invoke this by setting Charlie up with a cute blonde crewmember closer to his age, but Charlie is utterly disinterested.
* ScrewTheRulesIHaveSupernaturalPowers: Charlie Evans was given superpowers by the Thasians after his ship crashed and everyone else was killed. When the ''Enterprise'' picks him up, he has obsession with being liked and "removes" people from reality if they piss him off. Eventually the Thasians show up to take him back and repair the damage, but they're too late for a ship he destroyed that was trying to warn the ''Enterprise''. While Charlie repents in the end and promises never to use the powers again, Kirk and the Thasians agree that it's too much of a temptation.
* ShipperOnDeck: The latter part of Uhura's song comes a bit across as if she is this for Charlie and Rand. But maybe she, like everyone else at first, merely considers this amusing without taking it all too serious.
* SignificantReferenceDate: The episode was initially intended to air around Thanksgiving, hence the turkeys reference. However it ended up airing earlier due to it being the only completed episode at the time.
* SoreLoser: Spock crushes Charlie at chess, so Charlie uses his creepy mental powers to melt the pieces.
* SpiritualAntithesis: The episode can be seen as an antithesis of Robert A. Heinlein's novel ''Literature/StrangerInAStrangeLand'', which was published just five years before that episode aired. The plots of both works are essentially the same: an orphaned young man with nigh-omnipotent psychic powers is forced to adjust to human society after living his entire life among aliens, and finds himself entranced by the mysteries of human women. But while Heinlein's Valentine Michael Smith is a blissfully innocent figure who tries to use his powers to rid the human race of everything holding it back, ''Star Trek'''s Charlie Evans is a chillingly amoral figure whose alien upbringing leaves him incapable of using his powers responsibly. While Mike ends up successfully founding his own religion and social movement, Charlie is forcibly banished from human society for life.
* StalkerWithACrush: Charlie is one to Janice.
* StalkingIsLove: That's what Charlie thinks, anyway.
* StepfordSmiler: The captain of the ''Antares'' and his navigator, though eager to leave as soon as possible, are otherwise acting as if everything is fine. This may be partly so that Kirk doesn't get suspicious, but maybe also out of fear that Charlie will make them vanish too if they don't keep up a good mood.
* TheStoic: Spock doesn't think having his legs broken is worthy of mention until Kirk asks him to stand up.
* SufficientlyAdvancedAliens: The Thasians, who put everything right - except for the fate of the ''Antares'' - in about two minutes.
* TheTalk: Charlie's social awkwardness around girls is bad enough that Bones decides the boy needs to learn the rules. So he convinces Kirk to give it. And [[AnythingThatMoves Kirk]], of all people, gets too embarrassed to give it straight at all.
--> '''Kirk:''' There's no right way to hit a woman.
** In the third season, when he meets Elaan, Kirk seems to have changed his mind.
* UnnecessaryCombatRoll: Kirk demonstrates it for Charlie, and insists it's important when Charlie just wants to learn how to fight. Justified because Kirk is actually showing him how to fall safely when hit, which is just as important as being able to return the blow.
* VictoriasSecretCompartment: Charlie shows Yeoman Rand a "card trick" in which he tosses a card aside and makes it reappear down the front of her low-cut uniform. She's understandably startled and perhaps annoyed, given that the crew doesn't yet know about Charlie's powers and she can only assume that he pulled [[GettingCrapPastTheRadar a rather naughty bit of sleight-of-hand]].
* WildChild: Everyone assumed Charlie took care of himself from a very early age, explaining his horrible social conduct. Well, he did indeed have no ''human'' contact, so that does basically explain it.
* WoobieDestroyerOfWorlds: Charlie has NoSocialSkills, desperately wants to be liked and have friends, and has [[DisproportionateRetribution no sense of proportion]] when people don't treat him the way he wishes them to. Oh, and he is omnipotent. Picture a corporeal version of [[Series/StarTrekTheNextGeneration Q]] with NoSenseOfHumor and you have Charlie in a nutshell. The result is a maladjusted teenager who everyone is afraid of, who tries to make people like him by [[DramaticallyMissingThePoint punishing them whenever they make him unhappy.]]