The Breen-Dominion Alliance launches a devasting attack at the heart of the Federation, and the Federation Alliance struggles to maintain its foothold in Cardassian space. Kai Winn, under the guidance of Dukat, begins researching forbidden texts about the Pah-wraiths. On Cardassia, Damar begins a rebellion against the Dominion.

With the help of Kira, Odo, and Garak, the Cardassian Rebellion plots to steal a Breen weapon for the Federation. On DS9, Dr. Bashir and Chief O'Brien continue to try and find a cure for Odo, and Gowron's reckless attacks against the Dominion prompt Worf to take drastic action.