The later seasons of the series follow a war between the United Federation of Planets and the Dominion, an expansionist empire from the Gamma Quadrant, which has already absorbed Cardassia.
Sisko marries his fiancée Kasidy Yates, defying a warning from the Prophets that the marriage will bring sorrow; Gul Dukat, the former leader of Cardassia and now a worshipper of the Prophets' enemies, the Pah-wraiths, begins to win over the power-hungry Bajoran spiritual leader Kai Winn; and Deep Space Nine officers Ezri Dax and Worf are being held prisoner by the enigmatic aliens known as the Breen.
Dax and Worf, held prisoner on a Breen ship, continue arguing about their complex relationship, their recent ill-advised sexual encounter, and Jadzia's legacy.
Club notes interplay between two major threads dealing with religion, one with Sisko and Kassidy Yates, and another revolving around Kai Winn.
[2] They note Winn seems to use religion as justification for her corrupt and selfish ambitions, while Sisko confronts his convictions about Kassidy conflicting with his spiritual role to the Bajoran people, and there is also an interplay between these two plots.