The Galactica crew is overjoyed when they encounter another Colonial battlestar, the Mercury-class Pegasus. The elation fades when Admiral Cain takes command of the fleet. The Galactica crew learn about the harsh practices onboard Pegasus. The tension boils over when Helo and Chief Tyrol learn about Lt. Thorne, the "Cylon Interrogator."moreless
Kara arrives in the Blackbird with detailed photos of the mysterious Cylon ship. Despite the new truce between Adama and Cain, Roslin continues to see Admiral Cain as a dangerous threat, one that needs to be dealt with firmly.
With all others in the line of succession dead, Laura Roslin, the Secretary of Education, is appointed President of the Twelve Colonies. She plans to gather up all the ships that survived the Cylon attack, including the Galactica, and flee the Colonial homeworlds, never to return.
Sharon informs Adama that the Galatica has been infected with a computer virus that is tampering with the basic ship functions and is scanning them for weaknesses. All this is preparation for a major assault by the Cylon Raiders. So with the clock ticking, Adama must pull himself together and decide whether or not she can be trusted. Meanwhile the flight crew is hard at work on a new fighter named The Blackbird.moreless
The Cylons attack the battlestar Galactica and the rag-tag fleet exactly every thirty-three minutes, leading many to believe that there is a traitor in their midst.
Over forty years have passed since the end of the Cylon War, contested between the humans of the Twelve Colonies and man's creation, the Cylons.
The Galactica, one of the original twelve battlestars, is scheduled to be decommissioned. As part of the ceremonies, Commander Adama's son Lee ("Apollo") is named to fly Adama's restored Viper. Lee's return opens old wounds when they discuss the fate of Adama's other son, Zak.
Meanwhile, in Caprica City, the famous scientist Gaius Baltar argues against limits on research into artificial intelligence. He also has a sensual new lover with a mysterious agenda of her own.
Major Shaw has a dangerous plan to rescue a missing Raptor crew from a mysterious enemy. Meanwhile, Lee Adama realizes that Shaw was involved in a controversial military operation under Admiral Cain's command.
Apollo assists in the search for a missing Raptor team as the new commander of the Pegasus grows increasingly unstable.
The Galactica successfully reunites with the fleet, but the Cylons are still onboard the ship. Col. Tigh orders Lee to stop the Centurions from reaching Aft Damage Control before they vent the atmosphere from the ship. On Cylon-occupied Caprica, Starbuck and Helo visit her old apartment. Helo takes note of the abstract paintings on the wall. On Kobol, Baltar has a nightmare about Adama. Tyrol and Cally go on a supposed rescue mission.moreless
A week after last week's exciting episode, Adama returns to an excited CIC and retakes command of his ship. He orders a ship-to-ship search to find the President, but fails to find her before she sends out a message informing the other ships in the fleet that she knows where Earth is, and that she will lead them there. Over a third of the fleet leaves Galactica's protection and jumps back to Kobol to await the return of Starbuck.
Back on Caprica, Starbuck has been shot and is under medical care in a strange looking and sounding hospital.
Caprica Boomer returns to Helo, and helps him lead a raid on the hospital where Starbuck is being held which leads to a chilling discovery.moreless
Lee Adama, the new commander of the battlestar Pegasus, appoints the tough Lt. Kendra Shaw as his executive officer. Having served under the ruthless Admiral Cain, Lt. Shaw struggles with the lingering memories of those harsh times.
With Galactica on the verge of falling apart, Admiral Adama readies the ship for what could be its final mission, as Baltar's Six warns that humanity's final chapter is near.
A reporter is sent to Galactica to chronicle the harsh realities of life during wartime. Lucy Lawless guest stars as the television reporter, D'Anna Biers.
Tom Zarek has himself nominated for the role of Vice President while an assassin is discovered on the Cloud Nine Luxury liner. As tensions flare, the cruel hand of politics leads to murder, and the election of the most unlikely Vice President.
A woman takes hostages on Cloud Nine and demands that Adama turn over Sharon in order to avenge her husband's death at the hands of the Cylons.
Now onboard Galactica, Baltar faces charges of treason. He contemplates suicide with the help of Number Six. Questions remain about his true identity. Is he a Cylon or isn't he?
Apollo shows off the new drinking establishment on Galactica, Joe's Bar, to Tyrol. Apollo thinks about Kara and wonders whether his marriage to Dee is worth saving.