Torn between his duty and his people, Worf declines, prompting Gowron to excommunicate Worf's entire family. Worf then attempts to resign from Starfleet, but Sisko refuses to accept his resignation at this critical time. Sisko decides it's time to speak with Dukat, now part of the new government, and tells him that he will help escort the ruling council out of the war zone, even though, as Worf points out, he might actually be helping the Dominion. Sisko, Worf, Dax, and Bashir take the Defiant to a rendezvous point, where Dukat's ship is under heavy fire. The Defiant decloaks and prepares to attack the Klingons, ending two decades of peace.
While engaged in battle with the Klingon vessels, Sisko and his officers beam aboard the Cardassians, losing the Defiant's cloaking device in the process. They head back to the station with two Klingon ships in pursuit, while Bashir tests the blood of the council members to make sure they aren't Changelings. When they finally reach Deep Space Nine, several dozen Klingon ships arrive ready to attack.
Sisko prepares the station for the imminent onslaught. Martok demands for him to surrender the council members, but is told that the Cardassians are not Changelings. However, Gowron says that this doesn't matter because the Alpha Quadrant will be safer with Klingons in control of Cardassia. Sisko refuses his demands and warns Gowron that several weapons upgrades have been made to the station. Gowron dismisses the threat and the Klingons attack.
Deep Space Nine opens fire, inflicting heavy damage on the Klingon fleet, but Gowron doesn't give up, and Klingon boarding parties begin to overrun the station, fighting in Ops and on the Promenade. The attackers are contained, then several Starfleet ships appear on the scanners. Sisko points out to Gowron that splitting the Federation, the Klingons, and the Cardassians is probably just what the Dominion wants. Gowron sees the logic and opts to stand down, but tells Sisko that he will not forgive or forget what has happened. Afterward, Sisko convinces Worf to remain as his new Strategic Operations Officer. But Dax interrupts the celebration with some grim news. The Klingons are refusing to give up the Cardassian colonies they've seized, meaning they are there to stay.