The Enterprise is in danger when Janice Lester, one of Kirk's former lovers, steals his body.
While exploring the edge of the galaxy, the Enterprise encounters an energy barrier that gives two crewmen godlike powers.
Kirk and his crew are at deadly risk from an alien creature that feeds on the salt in a human body and can take on any form.
Nurse Christine Chapel is reunited with her old fiance on Exo III, but the scientist has plans for Captain Kirk and the Federation.
The Enterprise's newest passenger is a young man - what they don't know is that he has the power to make anything he thinks of happen.
The Enterprise picks up a distant distress call from a long lost ship that couldn't still have survivors so many years after it disappeared. Captain Pike leads a rescue mission only to discover that only one survivor remains living among a race of super intelligent aliens.
Kirk investigates an experimental facility for holding prisoners and finds a sinister scheme.
The Enterprise picks up a intergalactic conman, Harry Mudd, and three incredibly beautiful women who harbor a dark secret.
Kirk pits the Enterprise against an invisible spaceship testing the Federation's defenses.
Kirk attempts to assist a primitive people that are ruled over by a computer named Vaal.
The Enterprise discovers three discorporate intelligences who seek their help in gaining physical bodies... but one of them has plans of his own.
The Enterprise's command crew must thwart an invasion by aliens from another galaxy who plan to conquer this one.
Kirk, Spock, and McCoy become trapped in the past of another world.
The Enterprise is intercepted by a starship of unknown design and a woman from the ship beams directly into the bridge and uses a device to render the Enterprise's crew unconscious. She then walks over to Spock... When the crew awakens, McCoy summons Kirk to sick bay and informs him that the alien visitor apparently removed Spock's entire brain without even performing surgery. After Spock's body is fitted with a device that allows McCoy to control the Vulcan's motor functions with a remote control, Kirk starts a search for Spock's brain, hoping it can be recovered and somehow returned to Spock before his body decays.moreless
When the Enterprise investigates the disappearance of another starship, the crew loses Kirk in a dimensional interphase and must deal with a hostile alien race while trying to recover him.
The Enterprise encounters a planet whose culture is patterned on ancient Rome... and holds gladiatorial games that Kirk, Spock, and McCoy must fight in.
The Enterprise is taken over by a group of androids who are working for Kirk's old nemesis, Harry Mudd.
Kirk, Spock, and McCoy land on a primitive planet to negotiate a mining treaty, but soon find themselves involved with intrigue and must flee with a pregnant woman into the surrounding mountains.
The Enterprise must deal with a creature from Kirk's past that feeds on human blood.
The Enterprise must deflect an asteroid on a collision course with an inhabited planet... but discover the asteroid is a spaceship with a population unaware of the outside world.
Kirk, Spock and McCoy beam down to a planet in the path of an oncoming asteroid. However, Kirk disappears and the Enterprise is forced to abandon the search to stop the asteroid in time. Meanwhile, Kirk recovers consciousness but has no memories of his previous life, and is adopted by a local Amerindian tribe as their medicine chief and god.moreless
When the Enterprise brings aboard Klingon prisoners, an alien entity pits both sides against each other in an ever-escalating struggle.
The Enterprise travels to a planet where a scientific team has killed themselves... except for the children, who begin to act oddly.
The Enterprise picks up a group of space "hippies" looking for Eden.
A transporter malfunction causes Captain Kirk to split into his "good" and "evil" selves, and a landing party will freeze to death if the crew is unable to find a way to merge the two Kirks back together.
Kirk beams down on a diplomatic mission... and finds himself on an Enterprise where all the crew have vanished and only a mysterious woman resides.
The Enterprise must deal with discorporeal cloud-like aliens who have already destroyed the inhabitants of a library planet and plan to eliminate the Enterprise crew if they cannot acquire a human host.
The Enterprise finds itself host to two alien beings from the same planet, who share an intense and self-destructive hatred of each other.
The Enterprise must escort an alien princess to her marriage to seal an interplanetary alliance...but she becomes attracted to Kirk.
Kirk and his crew find themselves at the mercy of powerful individuals who possess mind-over-matter powers... and plan to use the Enterprise crew for their twisted entertainment.
Kirk, McCoy, and Sulu are stranded on a barren planet where a mysterious woman attempts to kill them one at a time, while the Enterprise must travel halfway across the galaxy to rescue them.
When a landing party investigating Scalos begins to vanish one by one, Kirk, Spock and McCoy try to find out what is happening before more of the crew disappears, until Kirk himself is abducted. Kirk finds the cause to be a group of endangered Scalosians who move faster than human sight or hearing can detect. They need to repopulate their species, and find that speeding human males up to Scalosian speed will meet their needs. Kirk must find a way to get a message to Spock and McCoy, who are working on a cure for the mystery "ailment," as well as stirring up fighting among the Scalosians, before they have control of the Enterprise.moreless
While seeking a cure for a fever ravaging the Enterprise, Kirk and Spock encounter Flint, a hermit-like Earthman, and his beautiful young ward.
Kirk and Spock meet Abraham Lincoln and Surak of Vulcan and must do battle with some of history's most terrible villains.
Stardate 5630.7:...or is there in beauty no truth? Miranda Jones, a telepath who studied mental disciplines on Vulcan, arrives with Ambassador Kolos, a Medusan - an alien life form whose physical form is so hideous, humanoid life forms are driven insane if they look upon him. Also beaming aboard is Larry Marvick, one of the original designers of the Enterprise - and hopelessly in love with Miranda, although she has chosen to spend her life serving as a liaison between the Medusans and other humanoids. Miranda senses that someone is actively contemplating murder, and suspects Spock is envious of her once-in-a-lifetime mission - but even Miranda is unaware of the real would-be killer and their target.moreless
The Enterprise encounters an alien who claims to be the Greek god Apollo.
A time accident leaves the Enterprise a UFO over 20th century Earth.
The Enterprise visits a colony where floral spores bring peaceful contentment.
A strange alien substance causes the crew to act out their deepest inhibitions, while the ship plummets out of orbit.
Kirk is one of the last survivors who can identify a mass killer, who lurks among a Shakespearean troupe aboard the Enterprise.
Kirk and a landing party are stranded on a planet due to a disease that causes any adult to die a painful death, and must deal with the local children who have survived.
The Enterprise encounters a vast alien ship that sets out to test them.
Spock kidnaps his former captain, the crippled Christopher Pike, and heads for a quarantined planet, putting his career and Kirk's life on the line.
Spock's court-martial continues as he attempts to justify his abduction of Pike, the theft of the Enterprise, and his heading for a planet declared forbidden by Starfleet.
Seven Enterprise crew members go on a shuttle mission with Spock in command.
The Enterprise crew take shore leave on a peaceful, pastoral planet... where their dreams and fantasies come to life.
The Enterprise discovers a rogue planet drifting through space, inhabited by an eccentric being named Trelane who uses his apparently unlimited power over matter and form to manipulate the crew.
The Enterprise must destroy an enormous space amoeba before it reproduces and threatens known space.
Captain Kirk becomes increasingly erratic and orders the Enterprise into Romulan space... where the ship is captured by a beautiful Romulan commander.
Starfleet uses the Enterprise to test a new super-sophisticated computer, but it soon develops a mind of its own.
The Enterprise encounters an ancient Earth probe bent on the sterilization of all life.
The Enterprise investigates the disappearance of another starship and discovers a planet where the inhabitants are immortal... and engaged in a strange parallel of Earth's Cold War period.
The Enterprise seeks out a historical researcher with whom the Federation has lost contact, and discovers he has contaminated a culture, remaking it into a near-duplicate of Nazi Germany.
The Enterprise travels to a planet suffering from cultural contamination from an earlier expedition--the inhabitants mimic the culture of 1920's gangland Chicago.
The Enterprise must stop an ancient doomsday weapon that is capable of destroying entire worlds... and has already totaled one Constellation-class cruiser.
On Eminiar VII, the Enterprise finds a civilization at war with its planetary neighbor. Unable to discern any signs of battle from orbit, Captain Kirk leads a landing party to the surface where he discovers the entire war is fought by computer. Even though the war is simulated, citizens who are listed as virtual casualties still report to termination booths to be killed for real. After the Enterprise is destroyed in an attack simulation, Kirk must fight to keep his crew from death.moreless
The Enterprise discovers a planetary population controlled by a powerful being called Landru. While investigating, Captain Kirk and his landing party are taken captive and discover that the Enterprise crew will be the next to be "absorbed" into Landru's control.
Spock meets his estranged father when the Enterprise escorts a group of ambassadors to a conference on the planet Babel.
When a landing party disappears and one man is beamed up dead, Kirk, Spock, and McCoy investigate and meet a pair of aliens who seem capable of performing magic.