(written from a Production point of view)
The Enterprise takes seventeen-year-old Charles Evans aboard for transport after he spent fourteen years alone on a deserted planet, but his inability to reintegrate with his fellow Humans is compounded by his very un-Human powers.
The USS Enterprise makes a rendezvous with the Antares, a small cargo ship. While investigating the planet Thasus, the Antares discovered an adolescent boy named Charles Evans, the sole survivor of a ship crash who has lived on his own since age three. Evans transfers to the Enterprise, which is on its way to Colony Alpha 5, where Evans' only relatives live.
Captain Ramart and his navigator and first officer, Tom Nellis, are eager to be on their way after beaming aboard the Enterprise, even refusing Captain Kirk's offer of Saurian brandy, as well as entertainment tapes. But they are also effusive in their praise of Charlie. Charlie interrupts Ramart and Nellis a couple of times, which prompts Kirk to say to him, "You keep interrupting, Mr. Evans. That's considered wrong." This encounter is the first of many mysteries surrounding the young man. Yeoman Janice Rand enters the transporter room and Kirk asks her to show Charlie to his quarters and to drop off his medical records at sickbay. Innocently, Charlie asks Captain Kirk if Yeoman Rand is a girl. "That's a girl," the captain replies. Rand escorts Charlie out, much to Kirk's amusement.
After a routine check-up by Dr. McCoy, Charlie attempts to learn and integrate, demonstrating the effect of his years away from all Human contact. At the same time, strange incidents occur in his vicinity. Charlie is also struggling mightily with adolescence and with his first crush, the beautiful Yeoman Janice Rand. After observing Wilson and a sciences division crewman slapping themselves casually, Charlie does the same to Yeoman Rand's behind in a corridor, angering her. After calming down, Rand advises Charlie to tell Captain Kirk or Dr. McCoy what he had just done and ask them for advice. Afterwards, in the Enterprise's recreation room on deck three, Uhura is singing "Oh, On the Starship Enterprise" to a rapt Rand and other crewmembers. Rand ignores Charlie's card tricks; he secretly uses his power to silence Uhura's voice, as well as the sounds coming from Spock's Vulcan lute, so that he can have Rand's undivided attention. He then proceeds with a few card tricks that amuse Rand and others in the crews' lounge, who applaud appreciatively.
Later, in a corridor, Kirk is advising a galley chef that on Earth today it is Thanksgiving, and if the crew of the Enterprise has to eat synthetic meat loaf, he wants it to look like turkey. Just then, Charlie arrives and tells Kirk of the trouble he had interacting with Rand earlier. Kirk awkwardly attempts to explain that men and women do things differently but before he can elaborate further to Charlie, Kirk is asked to come up to the bridge by Uhura.
At extreme range, Captain Ramart attempts to contact the Enterprise and speak to Captain Kirk, but before he can say more than "I've got to warn…", his ship is destroyed. Charlie advises Kirk that "It wasn't very well constructed" – a strange comment, since it comes before Spock actually confirms the Antares's destruction.
Kirk is then hailed by the Enterprise's chef, who tells the captain that he had put meat loaf in the ovens, but there are turkeys in them now – real turkeys. Charlie laughs at hearing this, then leaves the bridge abruptly, leaving Kirk feeling that Charlie is hiding something.
Kirk and Spock are pondering the destruction of the Antares during a game of three-dimensional chess when Charlie walks in and asks to play. After defeating Spock in an "illogical approach" to the game, Kirk turns it over to Charlie, during which Spock easily beats him in two moves. When Charlie gets angry, Spock leaves and then Charlie uses his powers to melt the white chess pieces. Afterwards, Rand introduces Charlie to Yeoman Tina Lawton, who is near Charlie's age. Charlie ignores Lawton, hurting her feelings, after which Rand tells Charlie that he was rude to her. Charlie then makes his feelings known to Rand that he wants her and only her, which makes the yeoman feel very uneasy. Rand goes to the bridge and wants Kirk to have a talk with Charlie before she asks the young man to leave her alone, which will hurt his feelings. Calling Charlie to his quarters, Kirk takes pity on the young man and attempts to befriend him, taking him to the physical training room for some light sparring. Initially refusing to participate, Charlie falls awkwardly and prompts laughter from Sam, Kirk's sparring partner. Humiliated and angry, Charlie makes Sam "go away", revealing his powers.
Kirk immediately calls for security to escort Charlie back to his quarters. But Charlie resists, knocking down the two security officers with his powers. One of them draws his phaser but Charlie makes it disappear but finally agrees to go to his quarters after Kirk tells the young man that he will personally pick him up and take him there himself if he does not. After Charlie and security leaves Kirk is informed by Uhura that ALL phasers on board the Enterprise have disappeared. Later, in the briefing room discussing Charlie to McCoy and Spock following the incident in the gymnasium, Kirk speculates that Charlie might be a Thasian, but McCoy doubts this based on his medical analysis results.
Charlie then enters and Kirk asks him outright if he was responsible for the Antares' destruction. Confronted, Charlie admits to destroying the Antares by making a warped baffle plate in its energy pile "go away". He defends his action by claiming that the ship would have blown up anyway, and that the crew weren't nice to him and tried to get rid of him. He leaves and Spock tells Kirk and McCoy, "We're in the hands of an adolescent."
Charlie, his powers now common knowledge, takes over control of the Enterprise, starting with Charlie causing Uhura's communication console to explode, preventing Kirk from sending a distress signal and causing Uhura second-degree burns on her hands. He wants to go to Colony 5; Kirk knows that the mayhem he would create in that unstructured setting would be far worse than what he's done so far on the Enterprise. Charlie then begins his reign of terror. Passing Yeoman Lawton in the corridor, he turns her into an iguana. He enters Rand's quarters with a pink rose (because he found out that pink was the yeoman's favorite color). When Rand tells Charlie to go away, he moves closer toward her, saying he only wants her. Rand is able to surreptitiously activate a communication device; on the bridge, Kirk and Spock hear the conversation leave the bridge to rescue Yeoman Rand.
Kirk and Spock rush to Rand's quarters and try to stop Charlie, but the teenager throws them against the wall, breaking Spock's legs in the process. A shocked Rand slaps Charlie, to which he responds by making her disappear. Charlie then releases both Kirk and Spock after he realizes that he needs Kirk's help to run the Enterprise. Rigging a force field, the crew attempt to trap and hold Charlie in his own quarters, but once he realizes an attempt has been made to confine him, Charlie easily escapes. He then goes on a rampage: he turns a young crewmember into an old lady and removes a young woman's face, leaving her groping in a corridor and still able to vocalize her terror.
Determined to stop Charlie before he can reach Colony 5, Kirk speculates that in taking over the ship, Charlie may have reached his limit. He thus attempts, with the help of Spock and McCoy, to overload the boy's abilities, ordering more and more of the ship's systems to be activated. In the midst of this struggle, a ship from Thasus appears. It is at this point that Charlie begs to stay with the Enterprise crew. The Thasians restore the Enterprise back to normal and return a confused Rand on the bridge. The Thasian explains to the bridge crew that they granted Charlie immense powers so he could live – powers that they cannot, or will not, remove. The Thasian expresses regret at the loss of the Antares, but at least can assure Kirk that his own crew, and ship, have been fully restored to him. Certain it would be impossible for Charlie to live a normal life with his own people, and despite Charlie's own pleas to stay with the crew, and even Kirk reconsidering his position that Charlie would never fit in among Humans, the Thasians remove him to their vessel and depart. Rand, with tears in her eyes, moves over to Kirk, seated in his captain's chair. "It's all right, yeoman. It's all over now," he says as the Enterprise moves on in space.
- "Captain's log, stardate 1533.6. Now maneuvering to come alongside cargo vessel Antares. Its captain and first officer are beaming over to us with an unusual passenger."
- "Captain's log, stardate 1533.7. We have taken aboard an unusual passenger for transport to Colony Alpha V. Charles Evans, the sole survivor of a transport crash fourteen years ago. The child, alone from age 3, has not only survived, but has grown to intelligent, healthy adolescence."
- "Captain's log, stardate 1535.8. UESPA headquarters notified of the mysterious loss of science probe vessel Antares."
"You keep interrupting, Mr. Evans. That's considered wrong."
- - Kirk, to Charlie upon his arrival on the Enterprise
"Is that a girl?"
"That's a girl."
- - Charlie and Kirk, on Rand
"There's no right way to hit a woman."
- - Kirk to Charlie, on slapping Rand's bottom
"If I had the whole universe, I'd give it to you. When I see you, I feel like I'm hungry all over. Hungry. Do you know how that feels?"
- - Charlie, to Rand
"There are a million things in this universe you can have and there are a million things you can't have!"
- - Kirk, to Charlie
"Sir, I put meatloaf in the ovens. There's turkeys in there now. Real turkeys."
- - Enterprise chef, to Kirk
"He's a boy in a man's body, trying to be an adult with the adolescence in him getting in the way."
- - Kirk, on Charlie
"There's a – Tyger, tyger, burning bright in the forest of the night."
- - Spock under Charlie's control, reciting "The Tyger"
"I'm trying to – Saturn rings around my head, don a robe that's Martian red."
- - Spock, still under Charlie's control
"Once upon a midnight dreary, while I pondered, weak and weary."
"Very nice, Mister Ears."
- - Spock and Charlie, as Spock recites Edgar Allen Poe's "The Raven"
"Growing up isn't so much. I'm not a man, and I can do anything! You can't."
- - Charlie to Kirk, after Rand vanishes
"I've waited long enough. I'm going to take him on!"
- - Kirk, referring to Charlie
"I can make you all go away… anytime I want to!"
- - Charlie to the bridge crew
"Don't let them take me… I – I can't even TOUCH them!"
- - Charlie, about the Thasians
"I want to stay…stay…stay…stay…"
- - Charlie's last words
Story and production
- Gene Roddenberry had written a one-sentence synopsis of this episode on the first page of his original series outline for Star Trek under the title "The Day Charlie Became God." The page is reproduced in the Herbert F. Solow/Robert H. Justman volume Inside Star Trek: The Real Story. Writer Dorothy Fontana also confirmed that the episode was based on that story idea. Fontana developed the story and wrote the teleplay, but Roddenberry received story credit. 
- This episode was originally scheduled to air further into the season, as all action took place aboard the Enterprise and it was basically a teenage melodrama set in the space age, both of which elements NBC hated. However, as it required no new outer space special effects shots (actually all Enterprise shots are recycled from the two pilots), its post-production took less time than other episodes, and it was chosen to be the second episode to air, out of necessity, as no other episodes were ready for the deadline. The Antares was originally to be shown on screen, however when the early airdate was commissioned, this was eliminated. (These Are the Voyages: TOS Season One)
- "Charlie X" was adapted for a novelization by James Blish. It was published in the first Bantam Books Star Trek novelization collection in 1967 under the name "Charlie's Law". (This name is a pun on Charles' Law, a law of physics dealing with how changes in temperature affect the volume of a gas.)
- The opening credits of this episode are the same as those used in "The Man Trap", which included a "Created by Gene Roddenberry" credit. The credits at the close of the episode only list Roddenberry as Producer. Also, the credits for William Shatner and Leonard Nimoy are missing the "starring" and "also starring" designations. This episode followed "The Man Trap" in airdate order. The main titles were standardized for syndication, however the DVD prints restore the titles to their original configuration.
- During the first-season episodes, cinematographer Jerry Finnerman was encouraged to maximize placement of colored background lighting to add exotic warmth to the gray walls of the Enterprise set. This was a major promotional point for NBC, as Star Trek was a selling point for color televisions. But as pressure to complete episodes grew, this touch gradually faded from the series. NBC was owned at the time by RCA, a major manufacturer of color television sets. (Inside Star Trek)
- This episode was directed by Lawrence Dobkin, who later guest-starred as Ambassador Kell in TNG: "The Mind's Eye".
- DS9 writer/producer Ira Steven Behr says that this is the episode that "won him over." (AOL chat, 1997)
- This was one of only three episodes of the first season that didn't show Vina in the last closing still. The other two episodes were "What Are Little Girls Made Of?" and "Dagger of the Mind".
- James Doohan (Scott) and George Takei (Sulu) do not appear in this episode, although two words of Takei's dialogue from "The Man Trap" are dubbed in when Kirk calls the bridge from the gymnasium.
- The galley chef was voiced by Gene Roddenberry, in his only acting role in Star Trek.
- In her autobiography, Grace Lee Whitney mentions that Robert Walker, (a method actor), completely avoided the cast on the set, trying to stay alone and "in character". "He explained to us when he arrived to the set that he wanted to remain alien and apart from us – and it worked. You can see it in his performance, a subtle yet persistent air of estrangement from the Enterprise crew, and indeed from the rest of humanity. His careful effort to stay in character added a convincing dimension to his performance." Furthermore, she added, "It's impossible to imagine anyone else in the role – he captured the perfect balance, projecting vulnerability, innocence and horrifying menace all the same time. A lesser actor could not have handled the range and depth of the character." (The Longest Trek: My Tour of the Galaxy, pp. 98-99)
- Fontana also praised Walker's performance, "[He] was excellent as Charlie. And he was quite a young man, he was in his twenties, but playing a teenager, he looked young enough to pull it off." 
- Allan Asherman, in The Star Trek Compendium, also mentions that Walker "turns in a powerful and fascinating performance". (p. 39)
- The role of Sam was to be initially played by Beau Vandenecker, but it was eventually recast to Robert Herron.
- Although it may not canonically represent the creative staff's intentions, the novelization by James Blish in Star Trek 1 identifies the unnamed crewman named Sam (whom Charlie "disposes" of) as Sam Ellis, an officer on McCoy's medical staff. The episode novelization made it clear that he, along with all of the officers who were disfigured of by Charlie, were "restored" along with Rand when the Thasians intervened. However, the USS Antares could not be saved because, as the Thasian explained, it was destroyed "in this frame" whereas the zapped Enterprise personnel were "kept intact in the next frame."
- This is the first of six original series episodes that takes place entirely aboard the Enterprise. The others are "The Changeling", "Journey to Babel" (Babel itself is never seen), "Elaan of Troyius", "Is There in Truth No Beauty?", and "Let That Be Your Last Battlefield". "The Doomsday Machine", "The Ultimate Computer", "The Immunity Syndrome", and "The Tholian Web" were also filmed using only the Enterprise sets, including that of the shuttlecraft interior, but some of the action in these episodes took place on other Constitution-class starships. By any reasonable definition, each of these entries qualifies as a bottle show.
- The grates in the floors of the corridors disappeared in later episodes. In one scene, Charlie takes great delight in watching a technician lower some tubing into one of these floor grates.
- In the scene in Rand's quarters, when Charlie flings Kirk and Spock against the wall, the wall has a hole punched in it. On an earlier take, Leonard Nimoy had struck the wall too forcefully.
- When Kirk and Charlie have their final confrontation, the camera moves to a rare floor-level view of the bridge. This close-up shows that the set is carpeted. This was probably done as a noise-absorber, given the propensity of the set to pick up noises like plumbing and squeaking floors. The material itself is Ozite, a portion of which was sold at the Profiles in History Star Trek auction in June 2002.
- The ship's gymnasium makes its first and only appearance in the series. It was originally intended to be seen in more episodes, as some of the shots showing acrobatics and gymnastics there were filmed as intended stock footage for reuse later. The gymnasium was a redress of the engineering set. The room where the gymnasts are tumbling is the redecorated briefing room.
- The bench on which Sam was sitting when he was zapped turned up later in other episodes. In "Court Martial", it held the wrench that Benjamin Finney snatched in his attempt to club Kirk. In "This Side of Paradise", it was topped off by the metal tray that Spock grabs during his fight with Kirk in the transporter room.
Props and special effects
- This is the only episode shot after the pilots to have no exterior views of the Enterprise using the updated "series" model. All of the shots are footage from "The Cage" and "Where No Man Has Gone Before".
- A large number of visual effects had to be nixed due to time constraints when the episode was moved ahead in airing schedule, to be broadcast in September (originally it was scheduled to air in November, hence the Thanksgiving reference). These included the Antares, which was called to appear on screen in the script, but ended up unseen. (These Are the Voyages: TOS Season One)
- Publicity stills of Grace Lee Whitney were used on the playing cards Charlie modifies. (The Star Trek Compendium, p. 39)
- After Charlie transforms Tina Lawton into an iguana, the noise the reptile makes was that of the sound made by Sylvia and Korob when they returned to their true forms at the end of "Catspaw".
- Spock's scanners in this episode make the same sound the Metron transmission does in "Arena".
- Like Trelane, Apollo, and the Gorgan, (other advanced beings whose powers threatened the crew) Charlie makes his exit with fading repetition of his final words.
- The music accompanying Charlie's disappearance at the end of this episode, highlighted by a mournful bassoon dirge, was re-used effectively in "Space Seed" as the landing party beams onto the Botany Bay; in "Patterns of Force" for the death of John Gill; in "The Tholian Web" as Chekov witnesses the dead engineering crew on the Defiant; as Kirk wanders the empty corridors of the faux-Enterprise early in "The Mark of Gideon"; and in "The Ultimate Computer" during Daystrom's final conversation with his M-5 computer.
- Charlie and the crew of the Antares are wearing old turtleneck uniforms left over from the two pilots. Also, when Charlie is causing panic on the corridors, crewmen can be seen wearing the new series shirts with old, pilot version trousers and boots. (The Star Trek Compendium, p. 39)
- For most of the episode, Charlie wears a gold wraparound jacket, which appears to be an unused, early version of Kirk's green tunic made for "The Enemy Within". It is apparently too big for him. (The Star Trek Compendium, p. 39)
- After this episode William Shatner only wore tights once more, in "Errand of Mercy". He later poked fun at his costume in this episode when clips of it were shown as part of the History Channel show, How William Shatner Changed the World.
- According to Kirk's line "On Earth today it's Thanksgiving", the beginning of this episode takes place on 22 November 2266 (assuming American Thanksgiving is meant).
- Still not firmly set in his characterization in this early episode, Spock shows both irritation and amusement as Uhura makes fun of him. It seems that he has learned how to express irritation ("Ah yes, one of your Earth emotions") fairly quickly since the events of "Where No Man Has Gone Before".
- The United Earth Space Probe Agency is referenced for the first time in this episode, with the acronym "UESPA". It was mentioned again in episode "Tomorrow is Yesterday". Years later, I AM ERROR referenced UESPA in several episodes, including "Demons".
- The line "Once upon a midnight dreary, while I pondered weak and weary" spoken by Spock while under Charlie's influence is the first line of the poem "The Raven", by Edgar Allan Poe. Spock is also forced to quote some lines from "The Tyger" by William Blake when he shouts that there is a "Tyger, Tyger burning bright, in the forests of the night". 
- The song that Uhura sings to Spock and then Charlie may have been taken from an old Scottish folk song penned by Robert Burns called "Charlie, He's My Darling". The chorus in that song is almost identical to what Uhura sings. 
Script vs. screen
- The first-draft script featured Uhura as a trained mimic, who amused crewmembers by parodying her fellow officers in the recreation room. It was later turned into her performing a song, to fit Nichelle Nichols' musical talents. (The Star Trek Compendium, p. 38)
- The second draft of this episode's script was completed on 27 June 1966, with the final draft coming in on 5 July. The episode itself was filmed in mid-July.
- The final draft script called for the Antares to be seen, dwarfed by the Enterprise. 
- A strange bit of dialogue present in the teleplay was cut from the episode: when discussing the possible existence of Thasians, and Kirk's possible father-figure behavior to Charlie, Spock satirically asked McCoy, "Shall I schedule you to give him voodoo and superstition lessons, doctor?" McCoy replied, "You can if he provides his own chicken's teeth and penguin feathers," to which Spock told him, "I'll see to it, doctor." 
- In the final draft script, a remnant of Uhura's mimicking of other crewmembers still remained; just before she sang, Rand suggested to her, "Do someone. Do the captain," but Uhura replied, "No, I've done him. Someone else… let's see…" It was then that Uhura started singing about Spock.
- In the final draft script, the card trick Charlie plays with Janice, which reveals her photograph on the cards, was not specified. The script simply stated that Charlie performed a variety of card tricks which amazed Janice and the onlookers. 
- Writer Dorothy Fontana recalled that the filmed episode was basically the same as her screenplay, "There were a few line changes, not much. The images of how Charlie affected people, you know, no face so a woman couldn't talk, things like that, those were all there [....] I noticed there really wasn't that much that was changed, it was pretty much the way I wrote it." 
- The preview contains an edited Captain's Log from the finished episode: "Captain's log, stardate 1533.7. We have taken aboard an unusual passenger . . . the sole survivor of a transport crash fourteen years ago."
- An alternate take of Charlie throwing Spock and Kirk against the wall in Yeoman Rand's quarters is included. The hole in the wall is still visible (Nimoy apparently hitting it too hard on a prior take or rehearsal), but while the final episode shows the start of the throw from the side, the preview shows it from the front.
- Actress Grace Lee Whitney listed this episode as one of her three favorites. "'Charlie X' brought out another side of me, the woman looking at a younger man. That was also wonderful because I felt an allegiance to Captain Kirk." (Starlog #105, April 1986, p. 49)
- Original story premise in Star Trek is...: 11 March 1964
- Story outline "Charlie Is God" by Gene Roddenberry: 23 April 1964
- Revised story outline: 28 August 1964
- Story outline "Charlie X" by Gene Roddenberry: 14 April 1966
- Story outline by Gene Roddenberry: 23 April 1966
- Story outline by D.C. Fontana: 27 April 1966
- Revised outline: 9 May 1966
- First draft teleplay by Fontana: 6 June 1966
- Second draft teleplay: 27 June 1966
- Staff rewrite: 30 June 1966
- Final draft teleplay by Gene Roddenberry: 5 July 1966
- Additional revisions: 11 July 1966, 13 July 1966
- Filmed: 11 July 1966 – 19 July 1966
- Day 1 – 11 July 1966, Monday (Half Day) – Desilu Stage 9: Int. Sickbay, Kirk's quarters
- Day 2 – 12 July 1966, Tuesday – Desilu Stage 9: Int. Corridors, Bridge
- Day 3 – 13 July 1966, Wednesday – Desilu Stage 9: Int. Bridge
- Day 4 – 14 July 1966, Thursday – Desilu Stage 9: Int. Recreation room (redress of Briefing room)
- Day 5 – 15 July 1966, Friday – Desilu Stage 9: Int. Transporter room, Janice Rand's quarters
- Day 6 – 18 July 1966, Monday – Desilu Stage 9: Int. Briefing room, Gymnasium (redress of Engineering)
- Day 7 – 19 July 1966, Tuesday – Desilu Stage 9: Int. Corridors (including Brig), Tie-down vfx shot of Abraham Sofaer
- Score recording: 29 August 1966
- Original airdate: 15 September 1966
- Repeated: 1 June 1967
- First UK airdate: 13 September 1969
The remastered version of "Charlie X" aired in many North American markets during the weekend of 14 July 2007. The episode included new effects shots of the Thasian ship, replacing the blob-like object seen on screen with a torpedo-shaped vessel. Most notably, the remastered episode opens with a shot featuring the Antares, a new design based upon the robot grain ships seen in the I AM ERROR episode "More Tribbles, More Troubles".
Video and DVD releases
- Original US Betamax/VHS release: 28 February 1985
- Original UK VHS release (two-episode tapes, CIC Video): Volume 5, catalog number VHR 2250, release date unknown
- US VHS release: 15 April 1994
- UK re-release (three-episode tapes, CIC Video): Volume 1.3, 8 July 1996
- Original US DVD release (single-disc): Volume 4, 19 October 1999
- As part of the TOS Season 1 DVD collection
- As part of the TOS Season 1 HD DVD collection
- As part of the TOS Season 1 Blu-ray collection
Links and references
- DeForest Kelley as Dr. McCoy
- Grace Lee Whitney as Yeoman Rand
- Nichelle Nichols as Uhura
- Charles J. Stewart as Captain Ramart
- Dallas Mitchell as Nellis
- Don Eitner as the Navigator
- Patricia McNulty as Tina Lawton
- John Bellah as Crewman I
- Garland Thompson as Crewman II
- William Blackburn as Hadley
- Frank da Vinci as
- Bobby Herron as Sam
- John Lindesmith as the helmsman
- Eddie Paskey as Leslie
- Gene Roddenberry as the file info of the galley chef
- George Takei as Sulu (voice only; recycled audio)
- Ron Veto as Harrison (aka "Engineer")
- Laura Wood as a Command crew woman 1 (old)
- Unknown actors as
- Unknown actresses as
- William Blackburn as the stand-in for DeForest Kelley
- Frank da Vinci as the stand-in for Leonard Nimoy
- Jeannie Malone as the stand-in for Grace Lee Whitney
- Eddie Paskey as the stand-in for William Shatner
2249; 2252; 4-0; "all right"; "all the time"; "a one-way street"; adolescence; adult; anger; answer; Antares; Antares-type; astrogator; astronaut; atmospheric system; baffle plate; biology; black; body; "Bones"; bow; captain's chair; card trick; cargo vessel; castaway; Charlie's parents; Charlie's relatives; Charlie's transport; century; check; checkmate; chess master; chess piece; chief; city; Colony Alpha 5 (Colony 5, Earth Colony 5); Colony 5 governor; Computer Statistics; confined to quarters; Constitution-class decks; coordinates; course; D channel; debris; deflectors; devil; door; dossier; duty; ear; earring; Earth; Earth history; Earthling; eating; electronic clipboard; energy pile; entertainment tapes; evidence; "excuse me"; exercise mat; exercise table; eye; falling; father image; female; first officer; fingers; flattery; floor; food concentrate; force field; forest; fracture; fruit; galley; guide; gymnasium; gymnastics; heart; home; Human; hunger; idea; iguana; immunity; Jefferies tube; judo; laser beacon; laughter; leg; legend; lesson; limb; logic; love; Martian; mathematics; meat loaf; memory banks; microtapes; million; mind; minute; mister; name; navigator; navigation console; neck; non-corporeal species; "Oh, On the Starship Enterprise"; oven; passenger; perfume; pink; playing card; Poe, Edgar Allan; poetry; power; present; probability; probe scanner; puberty; pugil stick; quadrant; quarters; range; "Raven, The"; record tapes; recreation room; risk; road; room; rose; Satan; Saturn; "Saturn Rings"; Saurian brandy; schedule; science-probe vessel; sensors; ship's stores; shoulder roll; slapping; society; solitaire; "sound of wind and limb"; space; starboard; status report; subspace frequency; subspace frequency three; subspace transmitter; survey ship; survivor; synthetic food; Thanksgiving; "thank you"; Thasian; Thasian ship; Thasus; three-dimensional checkers; three-dimensional chess; toes; towel; training program; transmission; transmutation; transport ship; transporter chief; throw; turkey; "Tyger, The"; UESPA headquarters (United Earth Space Probe Agency); universe; vegetable; Vulcan lute; wardroom; white; wind; word; year
Antarian metal chess pieces; bluejay; book; detention cell; chariot; Charlie's law; deck five; feathers; Ferndok; (gods); hell; helmet; hybrid; Jupiter; lab; librarian; library; meteoroids; microscope; pay; penguin; Phynburg Oscillating Framizam; rattle; Romulus and Remus; subspace radio; superstition; teeth; Tweedledum and Tweedledee; voodoo; Vulcan; wolf; "Wonderful One-Hoss Shay, The"; "Wynken, Blynken, and Nod"
- "Charlie X" at StarTrek.com, the official Star Trek website
- "Charlie X" at Memory Beta, the wiki for licensed Star Trek works
- "Charlie X" at Wikipedia
- "Charlie X" at MissionLogPodcast.com, a Roddenberry Star Trek podcast
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"The Naked Time"
| Star Trek: The Original Series|
| Next episode produced:|
"Balance of Terror"
| Previous episode aired:|
"The Man Trap"
| Next episode aired:|
"Where No Man Has Gone Before"
| Previous remastered episode aired:|
"Return to Tomorrow"
|TOS Remastered|| Next remastered episode aired:|
"The Squire of Gothos"