Capt. Pike is held prisoner and tested by aliens who have the power to project incredibly lifelike illusions.
The crew is stalked by a shape-shifting creature that drains the salt from humans. When it is unintentionally brought aboard, Scotty faces a decision.
Powerful teenage psychic Charlie beams aboard. Although wanting to be liked, he attacks others until the secret of his powers are revealed to Kirk.
As Kirk and Spock investigate a Starfleet tragedy, a friend of Kirk becomes endowed with godlike powers. To stop him, Kirk must hatch a risky plan.
A virus causes the Enterprise crew to lose all self-control, as Sulu threatens the crew with a sword, Spock cries and Bones looks for an antidote.
The Enterprise transporter malfunctions and beams Kirk onboard with his evil doppelganger. Later, Kirk and his crew are stranded on a frigid planet.
Kirk and the crew rescue Harry Mudd and three "mail-order brides" from his matchmaking service. Mudd tries to stop Kirk from bringing him to justice.
The Enterprise's search for famous scientist Roger leads Kirk to a deserted planet where Roger, who lives with two lifelike androids, turns on Kirk.
The Enterprise arrives at a planet where a virus puts humans in a chronic childlike state. When Kirk and his team become victims, only Bones can help.
A deranged doctor escapes to the Enterprise from a planetary penal colony. As Kirk investigates, he is brainwashed by the colony's maniacal director.
The Enterprise narrowly escapes from imposing alien Balok's starship, but when Balok transmits a distress call, Kirk and the crew go to his aid.
Spock abducts the Enterprise's injured former captain and sets a course for a forbidden planet. Facing a court-martial, Spock refuses to back down.
During Spock's court-martial, video images of Capt. Pike's encounter with the psychic Talosians reveals Spock's motivation for hijacking the ship.
Kodos, a fugitive mass murderer, is a 23rd-century Shakespearean actor. When a friend is murdered, Kirk asks a Shakespearean troupe to investigate.
After Romulan war birds destroy Federation outposts, the Enterprise pursues them. Similarities between them and Vulcans spark bigotry against Spock.
The Enterprise lands at a picturesque planet for shore leave, but the idyll is ruined when a samurai and a bloodthirsty knight attack Sulu and Bones.
Spock, Bones, Scotty and others crash-land on a planet where they're attacked by deadly giants. Spock risks their lives on a slim chance at a rescue.
When the Enterprise is captured on a planet ruled by a childish alien who is fascinated with Napoleon, Kirk offers his life for his crew's freedom.
Aliens abduct Kirk and a Gorn, a violent, lizard-like humanoid. To save their crews, Kirk and the Gorn must fight to the death, but Kirk refuses.
A black star sends the Enterprise back in time to 1960s Earth. Before they can turn back, Kirk and the crew must destroy all evidence of their visit.
After an officer is killed in a freak accident, computer records indicate Kirk is to blame. Evidence at a court-martial reveals that Kirk was framed.
When the Enterprise travels to a planet where a Starfleet ship disappeared years ago, they find a tyrannical computer that rules its oppressed people.
The Enterprise encounters brutal super humans led by Khan Noonien Singh, who battles Kirk for control, turning a trusted colleague against Starfleet.
Arriving at a planet where his crew members are slated to die, Kirk learns they're in a virtual war in which suicide is commited to avoid real combat.
The Enterprise lands on a planet where everyone becomes very passive and affectionate toward one another. Kirk soon learns the cause.
When a monster kills several men at a mining colony, Kirk and Spock investigate. Spock learns the odd creature is intelligent, with a valid motive.
Kirk tries to establish an outpost on a planet inhabited by seemingly primitive Organians. When Klingons attack, Organians show their true evolution.
Kirk meets Lazarus, who claims he's chasing his parallel self through space and time and if Kirk doesn't help him, the entire multiverse is at risk.
Bones travels back to 1930s America and inadvertently destroys the future. To reverse the damage, Kirk and Spock also go back, and Kirk falls in love.
On another planet, Kirk's brother is killed by amoeba-like aliens, which also infect Spock. But Bones's cure has surprising side effects.
When a mysterious intruder on the Enterprise cunningly steals Spock's brain, Bones tries to keep the Vulcan alive while Kirk tracks down the thief.
On Kirk's orders, the Enterprise deliberately crosses the Neutral Zone into Romulan space and is promptly surrounded by Romulan warships.
Trapped on a planet whose inhabitants resemble Native Americans, Kirk loses his memory and is proclaimed a god.
The Enterprise reaches a Federation colony where the adults have all killed each other but the children play without care.
The Enterprise transports the Medusan ambassador Kollos; his telepathic interpreter, Dr. Miranda Jones; and engineer Laurence Marvick.
As punishment for trespassing on their planet, the inhabitants condemn Capt. Kirk and his landing party to reenact the Gunfight at the O.K. Corral.
An entity traps the Enterprise crew and the crew of a disabled Klingon battle cruiser in an unending war aboard the Enterprise.
The Enterprise discovers that an apparent asteroid on a collision course with a planet is actually an ancient populated generation ship.
Kirk and the derelict starship Defiant vanish into a spatial interphase between universes.
On an urgent medical emergency, Kirk, Spock and McCoy encounter an alien society that had once flourished on Earth during the time of Plato.
The Enterprise responds to a distress call from the planet Scalos, but when landing party members beam down, they find no living beings.
Trapped in an alien laboratory, Kirk, Spock and McCoy meet an empath and are involved in a series of experiments.
The Enterprise transports Elaan, a member of the ruling dynasty of the warrior Elasians, to the planet of their enemy, the Troyians.
Kirk and Spock are taken prisoner by a former starship captain who now resides at -- and has taken over -- an asylum for the criminally insane.
The Enterprise encounters two duo-chromatic and mutually belligerent aliens who put the ship in the middle of their old conflict.
Kirk beams down to the planet Gideon and appears to find himself trapped on the deserted Enterprise.
After Enterprise landing party members beam down to investigate a geologically interesting planet, their ship is hurled across the galaxy.
The Enterprise is on course to install new equipment on Memory Alpha, the central library storage facility for the Federation.
Kirk, Spock and McCoy beam down to a supposedly uninhabited planet to gather the mineral ryetalyn to fight a plague of Rigelian fever.
The Enterprise is ordered to pursue a group of antiestablishment idealists who have stolen a space cruiser.
Kirk and Spock are caught up in a revolution on a planet where intellectuals and artists live in a utopian city in the sky.
Kirk, Spock, Abraham Lincoln and Surak are pitted in battle against four notorious villains from history.
The planet Sarpeidon is about to be destroyed by its star, Beta Niobe, becoming a supernova.
Kirk is confronted with the deep hatred of an old love, Janice Lester, who is severely ill from celebium radiation.
In the throes of his Pon Farr mating period, Spock must return to Vulcan to meet his intended future wife, betrothed from childhood.
A powerful being claiming to be the Greek god Apollo appears and demands that the crew disembark onto his planet to worship him.
An artificially intelligent probe with a murderously twisted imperative comes on to the Enterprise and confuses Capt. Kirk with his creator.
Kirk, McCoy, Scotty and Uhura find themselves in a mirror universe aboard a parallel Enterprise run by ruthless barbarians.
Kirk and a landing party beam down to what seems to be an ideal, Eden-like planet.
The Enterprise encounters the wrecked Constellation, whose distraught captain is determined to stop the giant ship that killed his crew.
When Kirk and his landing party arrive on the planet below, they are met with eerie mists, a dark castle, witches, goblins and a black cat.
Harry Mudd returns with a plot to take over the Enterprise by stranding the crew on a planet populated by androids under his command.
The Enterprise crew members encounter a mysterious energy cloud that pulls them down to planet Gamma Canaris N, where they meet a castaway.
The Enterprise hosts a number of quarrelling diplomats -- including Spock's father -- but someone on board has murder in mind.
The Federation is in competition with the Klingons for an alliance with the inhabitants of Capella IV, a warrior tribe.
Landing party members from the Enterprise are exposed to a strange form of radiation that rapidly ages them.
Capt. Kirk obsessively hunts for a mysterious cloud creature he encountered in his youth.
Scotty is suspected of murdering a belly dancer.
Kirk must deal with Federation bureaucrats, a Klingon battle cruiser and a peddler who sells furry, purring, hungry little creatures as pets.
Kirk, Uhura and Chekov are captured and enslaved on a distant planet, where they're trained to perform for the amusement of bored, faceless aliens.
Kirk, Spock and McCoy beam down and find themselves in a culture similar to Earth gangs of the 1920s.
The Enterprise encounters a gigantic, energy-draining space organism that threatens the galaxy.
Kirk returns to the planet Neural, where he spent time 13 years earlier. A friend of Kirk's from his previous visit is now the leader of its people.
The last three members of an ancient race far more advanced than humans wish to borrow the bodies of Kirk, Spock and Dr. Mulhall.
Looking for a missing Federation cultural observer, Kirk and Spock find themselves on a planet whose culture is modeled on the Nazi Party.
Kirk, Spock, McCoy and a couple of red shirts beam down to the surface of a planet in answer to a fake distress call.
Kirk finds Capt. Tracey of the USS Exeter violating the prime directive and interfering with a war between the Yangs and the Kohms.
The Enterprise is chosen to be the test ship for the new M-5 multitronic computer system, which is designed to run a ship without human help.
The Enterprise discovers a planet whose oppressive government is a 20th-century version of Earth's Roman Empire.
The Enterprise is assigned to observe Earth's history in 1968.