A Klingon fleet arrives at the station and Worf becomes part of the crew.
A Klingon fleet under General Martok arrives at the station, saying it has come to help defend against the Dominion. Klingon troops cause trouble on the station, beat up Garak and search ships for Changelings, and Sisko has to use the Defiant to back them off.
Sisko calls in Lieutenant Commander Worf, who is thinking of leaving Starfleet, to find out what the Klingons really want. Worf learns that they plan to invade Cardassia, where a civilian council has overthrown the military government, because they believe the Dominion was behind the change. Sisko lets Garak overhear the news so he can warn Cardassia, and when the Federation condemns the attack, the Klingons pull out of the Khitomer Accords. Gowron asks Worf to join the invasion, and Worf's refusal costs his family its standing in the Empire.