When Captain Sisko leads the Defiant on a dangerous mission into the Gamma Quadrant to liberate a conquered world, the Bajoran government insists that Kai Winn, the Federation's long-time nemesis, assume complete control of the space station. Left behind by Sisko, Major Kira expects the worst from the Kai's new regime, but even she is caught by surprise when a fleet of alien warship attack Deep Space Nine!

Major Kira and the ambitious Kai Winn have never seen eye to eye, but when Cardassian renegades invade Deep Space 9, determined to capture one of the sacred Orbs of the Prophets, the two women must work together to preserve both the Orb and the safety of everyone aboard the station. Captain Sisko and the crew of the USS Defiant cannot come to Kira's aid; they are too busy teaching an entire world how to fight back against a vicious invasion – even if it means breaking the Prime Directive!