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.

While exploring the edge of the galaxy, the Enterprise encounters an energy barrier that gives some crewmen strange powers.

A strange alien substance causes the crew to lose their inhibitions.

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.

Kirk investigates an experimental facility for holding prisoners and finds a sinister scheme.

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.

Spock commands a stranded away team when their shuttlecraft is stranded on a planet with hostile natives.

The Enterprise finds itself at the mercy of a seemingly omnipotent being who fancies himself an 18th century Englishman.

When a mysterious alien race destroy an Earth colony, the Enterprise pursues, but Kirk and the alien captain are forced to fight each other by powerful aliens.

In a freak accident the Enterprise is sent back to 20th century Earth, and must find their way back without changing history.

Captain Kirk's career is at stake when he is put on trial for the loss of a crewman during an ion storm.

The Enterprise encounters a seemingly peaceful civilization run by a "benevolent" being named Landru... who intends for them to join his people.

The Enterprise arrives at a planet to establish diplomatic relations and finds itself in the middle of a "peaceful" war that threatens to destroy the ship.

The Enterprise crew try to rescue colonists from deadly radiation, but instead encounter strange alien spores that seem to offer paradise.

Kirk investigates a series of grisly murders on a mining planet that are the work of a seemingly hostile alien creature.

The Federation and the Klingon Empire teeter on the brink of war as Kirk investigates Organia, a humble planet, inhabited by pacifists, that is unwittingly caught in the middle.

Kirk and Spock encounter an alien named Lazarus who claims to be from an anti-matter universe.

Kirk and Spock must travel into the past in order to correct a change that will alter history.

Kirk and the Enterprise must combat parasitic aliens threatening the lives of millions.

The crew of the Enterprise are on a secret mission to steal a Romulan cloaking device.

The crew of the Enterprise encounters an ageless and sadistic race of humanoids with the power of telekinesis and who claim to have organized their society around Ancient Greek ideals.

Invisible "time-accelerated" aliens take over the Enterprise and attempt to abduct the crew for use as "genetic stock".

Strange incorporeal aliens threaten the Memory Alpha station and the Enterprise.