Dr. McCoy discovers his old flame is not what she seems after crew members begin dying from a sudden lack of salt in their bodies.

Captain Kirk must learn the limits to the power of a 17-year-old boy with the psionic ability to create anything and destroy anyone.

The flight recorder of the 200-year-old U.S.S. Valiant relays a tale of terror--a magnetic storm at the edge of the galaxy.

The crew is infected with a mysterious disease that removes people's emotional inhibitions to a dangerous degree.

A transporter malfunction splits Captain Kirk into two halves: one meek and indecisive, the other violent and ill tempered. The remaining crew members stranded on the planet cannot be beamed up to the ship until a problem is fixed.

The Enterprise picks up untrustworthy entrepreneur Harry Mudd accompanied by three beautiful women who immediately put a spell on all the male crew members.

Nurse Chapel is reunited with her fiancé; but his new obsession leads him to make an android duplicate of Captain Kirk.

The Enterprise discovers a planet exactly like Earth, but the only inhabitants are children who contract a fatal disease upon entering puberty.

Kirk and psychiatrist Helen Noel are trapped on a maximum security penal colony that experiments with mind control and Spock must use the Vulcan mind-meld to find a way to save them.

After the Enterprise is forced to destroy a dangerous marker buoy, a gigantic alien ship arrives to capture and condemn the crew as trespassers.

Spock kidnaps the disabled Capt. Pike, hijacks the Enterprise, and then surrenders for court martial.

At Spock's court martial, he explains himself with mysterious footage about when Capt. Pike was kidnapped by powerful illusion casting aliens.

While Captain Kirk investigates whether an actor is actually a presumed dead mass murderer, a mysterious assailant is killing the people who could identify the fugitive.

The Enterprise must decide on its response when a Romulan ship makes a destructively hostile armed probe of Federation territory.

The past months have left the crew exhausted and in desperate need of a break, but does this explain McCoy's encounter with a human-sized white rabbit or Kirk crossing paths with the prankster who plagued his days at Starfleet Academy?

The Galileo, under Spock's command, crash-lands on a hostile planet. As the Enterprise races against time to find the shuttlecraft, Spock's strictly logical leadership clashes with the fear and resentment of his crew.

A being that controls matter and creates planets wants to play with the Enterprise crew.

For bringing hostility into their solar system, a superior alien race brings Captain Kirk into mortal combat against the reptilian captain of an alien ship he was pursuing.

The Enterprise is thrown back in time to 1960s Earth.

Kirk draws a court martial in the negligent death of a crewman.

Seeking the answer to a century-old mystery, Kirk and crew encounter a vacantly peaceful society under a 6000-year autocratic rule that kills all those it can't absorb.

While on patrol in deep space, Captain Kirk and his crew find and revive a genetically-engineered world conqueror and his compatriots from Earth's Twentieth Century.

Kirk and Spock must save their ship's crew when they are all declared killed in action in a bizarre computer simulated war where the actual deaths must nevertheless occur.

The Enterprise investigates a planet whose colonists should be dead, but are not.

The Enterprise is sent to a mining colony that is being terrorized by a mysterious monster, only to find that the situation is not that simple.

With a war with Klingons raging, Kirk and Spock attempt to resist an occupation of a planet with incomprehensibly placid natives.

Existence itself comes under threat from a man's power-struggle with his alternate self, with the Enterprise's strained dilithium crystals presenting his key to a final solution.

When a temporarily insane Dr. McCoy accidentally changes history and destroys his time, Kirk and Spock follow him to prevent the disaster, but the price to do so is high.

The Enterprise crew attempts to stop a plague of amoeba-like creatures from possessing human hosts and spreading throughout the galaxy.

Capt. Pike is held prisoner and tested by aliens who have the power to project incredibly lifelike illusions.