Season synopsis
Contains spoilers for this season and earlier seasons.
Sisko’s mission to expose a Changeling inside the Klingon leadership begins with the wrong suspect. Disguised as Klingons, his team targets Chancellor Gowron, but Odo realizes that General Martok is the impostor. The Changeling is killed, and Gowron agrees to a ceasefire with the Federation. The Dominion’s attempt to take control through an assassination fails, although the threat beyond the wormhole remains and Cardassia soon becomes its foothold in the Alpha Quadrant.
Sisko also pursues Michael Eddington, the former Starfleet officer now fighting for the Maquis. When Eddington poisons Cardassian colonies, Sisko retaliates against a Maquis world and threatens others until Eddington surrenders. Meanwhile, Dukat announces that Cardassia has joined the Dominion under his leadership. Worf, Garak, the real Martok and Bashir are held in a Dominion prison camp, revealing that the doctor aboard the station has been replaced. The prisoners escape, and their warning helps Sisko stop the impostor’s plan to destroy Bajor’s sun. Gowron restores the Federation–Klingon alliance.
By the finale, Dominion reinforcements are crossing the wormhole into Cardassian territory. Sisko orders a self-replicating minefield laid across the entrance, knowing that the Dominion will attack the station to remove it. He supports a non-aggression pact for Bajor to keep the planet outside the coming war. Once the mines are active, Starfleet evacuates Deep Space Nine. Jake stays as a reporter, and Kira, Odo, Quark and Rom remain under the occupiers. Dukat takes Sisko’s office, finding the baseball left as a promise of return, while the Defiant joins the Federation and Klingon fleet.