Galactica has succeeded in reuniting with the Fleet, but at a serious price. A Cylon computer virus has penetrated its computers, robbing the ship of power, and Cylon Centurions have boarded Galactica and are battling their way to the ship’s control centers. Colonel Tigh knows the Cylons’ strategy from experience—they’re going to kill the crew by venting the ship’s air and then turn its guns on the rest of the Fleet.
Lee Adama, stuck in the brig with President Roslin, manages to persuade some marines to release them. He orders Billy to take the president to safety, then heads off with a squad of marines to defend the ship’s magazines.