The crew fights for survival when a mysterious force attacks the ship's life support systems. The answer appears to be related to microscopic machines known as Nanites which have escaped from Wesley's latest science experiment.
The Enterprise discovers a human colony living on a planet bathed in lethal radiation. Unfortunately an alien race believe the planet to be theirs under a treaty with the Federation, who knew nothing of the colony when the treaty was signed. As the only member of the crew immune to the radiation, Data goes down to the surface to convince the colonists to leave, but can he overcome their prejudice and save them?
The crew travels to Rana IV, a remote colony where just two of its 11,000 inhabitants have miraculously survived a devastating attack by an unknown race. When the alien attackers return, the Enterprise crew become suspicious that all is not as it seems.
After an accident at a research station watching the development of a proto-Vulcan race, the Enterprise is forced to intervene. Mistakenly believing Captain Picard to be a god, the members of the primitive culture seize Counselor Troi and prepare to sacrifice her to the Picard god.
When the ship's archaeologist is killed on a mission led by Lt Worf, the Klingon feels responsible for the son she left behind. However Worf is not the only one trying to make amends...
The Enterprise is caught in a booby trap that captures the ship and converts its energy into lethal levels of radiation. In the search for a solution, Geordi calls up a simulation of one of the designers of the Galaxy class starship, Leah Brahms, in the holodeck.
After Geordi is stranded on a storm-ravaged planet, the crew's attempts to rescue him are hindered by an aggressive Romulan warbird.
Geordi discovers a Romulan who is also stranded, and the two learn they must put aside their differences if they are to survive.
Counselor Troi is swept off her feet by a dashing delegate who uses unethical methods to conduct his business on board the Enterprise. Meantime, the crew investigate the reality of the apparently stable wormhole that is the subject of an auction. A group of Ferengi scientists go into the wormhole, cavalierly ignoring the Enterprise's suggestions of caution.
The crew's attempts to mediate a violent dispute between warring clans is sabotaged by a mysterious assassin who is genetically engineered to be fatal to members of the other clan.
A Romulan defector leads the crew into a showdown that could erupt into a full scale war. Is he really the lowly clerk he claims to be?
The Enterprise is bombarded by a soldier who is the victim of a government mind control technique which turns him into a violent killer with exceptional powers. Treated like a criminal because they cannot reverse his condition, he and others like him seek to escape from their prison.
Doctor Crusher's abduction by a radical terrorist group thrusts the crew into an explosive civil war on Rutia Four. Riker attempts to negotiate for her return but only drags the Federation deeper into the conflict, during which time Picard is captured and a bomb is placed on the Enterprise.
The crew is surprised by the appearance of their mischievous nemesis, ``Q'', who it appears has been stripped of his powers by the Q Continuum, and is sent to the Enterprise as a lowly humanoid.
Riker is suspected of murdering a respected scientist who had accused the Enterprise officer of seducing his wife. Is Riker really a killer or was the scientist trying to hide something?
The course of history is altered when a time rift brings the previous starship Enterprise (NCC-1701-C) from the past into the present. In the alternate time line, Tasha Yar is still alive and the Federation is losing a war against the Klingon Empire.
Data becomes a father when he creates an android using a transfer of his own neural programming. Things become complex when Starfleet decides it must adopt the new android, Lal, and take her to a research establishment.
When his long-lost brother, Kurn, appears on the Enterprise, Worf is thrust into a life-or-death battle for his family's honor against Duras, leader of one of the most important families in the Klingon Empire.
Without the crew's knowledge, Captain Picard is kidnapped and replaced by an impostor. While the impostor attempts to investigate how near he has to come to destroying the Enterprise to provoke a mutiny, Picard is trying to escape from the cell where he and some aliens are being held captive.
While on vacation on the holiday world Riza, Picard becomes entangled with a young woman (Vash) involved in a dangerous search for a missing weapon from the future.
The crew is thrust into a deadly showdown with the Romulans over a newly discovered life-form in a remote star system. They are also concerned at the Federation's Betazoid ambassador who has a history of mental illness and failed missions.
The crew struggles to help a young engineer, Reg Barclay, whose obsession with his fantasy world on the Holodeck is endangering the ship.
The crew leave Data for dead when his shuttle craft explodes during a dangerous mission. In reality, he has been abducted by a collector who specialises in the Unique and sees Data as the greatest prize.
The Enterprise is plagued by an outbreak of violence when it is visited by the renowned Vulcan ambassador, Sarek Discovering that Sarek is dying from an incurable disease, Picard must mindmeld with Sarek to allow him to complete a last vital negotiation for the Federation.
The Enterprise is thrown into chaos when Commander Riker, Counselor Troi and Troi's mother Lwaxana are kidnapped by the Ferengi.
The Enterprise rescues a mysterious humanoid whose remarkable powers affect the entire crew. After restoring his health, they must face the possibility that he is a wanted criminal.
Following on from the Enterprise's encounter with the Borg (in the episode Q Who), the Borg arrive in Federation space to ``assimilate'' the Federation's people and technology.
They capture Captain Picard in an attempt to conquer the human race, and set course for Earth. Riker, who is now acting as Captain, must find a way to stop them before the Enterprise has to break off the pursuit.