When a ship sending a Priority-1 distress signal, emerges from the wormhole with a Klingon ship hot on their trail, Captain Sisko takes a team and heads out on the Defiant. Though there're no survivors on board, the crew finds clues that lead them to believe the Founders are up to something in the Gamma Quadrant. Sisko heads out in the Defiant again to check it out, leaving Worf and O'Brien in charge of the station. Suddenly, the station is attacked by Klingons who capture almost everyone. With the Defiant away on a dangerous mission, the station is at its most vulnerable-and only the combined efforts of O'Brien, Worf, and Bashir can Deep Space Nine from Klingon domination.