When the Klingons establish a presence on Deep Space Nine and in Bajoran space, Captain Sisko brings Worf to the station to advocate the Federation's cause.

Worf is stuck between the Empire and the Federation when the Klingons launch a full-scale invasion of Cardassia. Sisko attempts to rescue Cardassia's leaders, bringing the fury of the Klingons down on the station.

Many years into the future, an aged Jake Sisko tells the story of his father's fateful disappearance into subspace -- and his obsessive desire to get him back.

Bashir and O'Brien crash land on a planet in the Gamma Quadrant and are captured by rogue Jem'Hadar, who are trying to break the drug addiction that keep them enslaved.

Kira and Dukat seek out a ship of Bajoran prisoners lost six years ago, which Kira discovers included Dukat's Bajoran mistress and their young daughter.

Jadzia meets the new host of Torias Dax's wife when a group of Trill scientists arrive, and faces the taboo that prevents Trill hosts from reconnecting with loved ones from their former lives.

The crew takes the Defiant into the Gamma Quadrant for trade negotiations, only to find themselves in a cat-and-mouse hunt with a pair of Jem'Hadar warships in the atmosphere of a gas giant.

After acquiring a ship of his own, Quark takes Rom and Nog for a test flight to Earth -- only to find themselves prisoners of the U.S. military in the year 1947.

Worf joins Dax and the legendary Klingon warrior Kor in a search for the lost sword of Kahless, a mythical weapon they hope will unseat Gowron and unite the Klingon Empire.

A transporter accident forces the station to save Sisko, Kira, Dax, Worf, and O'Brien's patterns to the holosuite systems -- where they unexpectedly appear as characters in Dr. Bashir's twentieth-century spy novel.

Evidence of a Changeling found on Earth sends Sisko and his team back home, where they hope to convince the Federation President to implement new security measures. Meanwhile Ben and Jake have a personal homecoming with Ben's father in New Orleans.

After Starfleet security forces are deployed throughout Earth due to the Changeling threat, Captain Sisko and Odo grow suspicious that the real danger to the Federation may lie within.

When First Minister Shakaar visits the station to negotiate with the Federation, Odo is forced to come to terms with his feels for Kira when faced with a competing suitor.

A routine diplomatic voyage leads Kira and Dukat to a hunt for a Klingon Bird of Prey, as the former Gul seeks to restore his position in the Cardassian military.

Worf's brother Kurn arrives on Deep Space Nine to undergo ritual suicide. Kira and O'Brien investigate suspicious Klingon activity near Bajoran space.

Rom leads Quark's employees in forming a union after he drastically cuts their pay, bringing down the wrath of the Ferengi Commerce Association.

A legendary poet makes a surprise return to Bajor, claiming that the Prophets have appointed him to be the Emissary and reinstituting a defunct cast system to try and return Bajoran society to its former glory.

Commander Worf faces a hearing led by a Klingon advocate wanting to extradite him to the Empire for trial, accusing him of murdering over 400 civilians when he destroyed an unarmed transport ship in the midst of battle.

Miles O'Brien must readjust to his life on the station after living for 20 years in an alien prison -- only to learn that his punishment was only programmed into his memory.

Captain Sisko must follow his son into the mirror universe when his late wife's double convinces Jake to visit her reality, and finds himself blackmailed into helping the resistance finish their Defiant.

Jake meets an alluring woman who tells him she can help him with his writing -- but who is certainly more than she appears to be. Odo comforts Lwaxana Troi when she arrives on the station ... pregnant.

Sisko learns that his girlfriend, freighter captain Cassidy Yates, is suspected of collaborating with the Maquis.

Sisko forges an alliance with a group of Jem'Hadar to track a group of renegade Jem'Hadar, who are seeking to repair an Iconian gateway that could allow them to control the galaxy.

Julian commits himself to finding a cure to a plague on a ravaged world in the Gamma Quadrant -- but it may be more than even he can handle.

Quark reexamines his life when he learns that he has a fatal disease, and decides to auction off his remains. An accident forces Dr. Bashir to transfer Keiko's baby to Major Kira.

A mysterious illness forces Odo to return to the Great Link, the home of the Changelings -- where he is judged for his past crime.