When an old enemy, the Cylons, resurface and obliterate the 12 colonies, the crew of the aged Galactica protect a small civilian fleet – the last of humanity – as they journey toward the fabled 13th colony, Earth.
Lt. Sharon Valerii wakes up soaking wet in the tool room with an explosive charge in her duffel bag. Shortly afterward, a mysterious explosion destroys all the port-side water tanks on Galactica, creating a crisis for the entire fleet. Sharon can’t remember a thing, but all the evidence points to her as a saboteur. She confesses her concern to Chief Tyrol, but he can’t believe she’s responsible.
Gaius Baltar sets off a debate on religious freedom when he promotes his belief in a single God.
Specialist Tyrol continues to sink into despair after his recent loss. He becomes curious about Gaius Baltar’s sermons and the following he has attracted. The crew of the Demetrius grow concerned about Kara’s mental stability as an old enemy arrives with a tempting offer.
Colonial Viper pilots plan an attack on the Resurrection Hub with their Cylon rebel allies.
Ellen escapes from Cavil only to face a momentous choice regarding the 13th Tribe and the Final Five Cylons.
President Roslin’s fears that Commander Adama is a Cylon are stoked when she learns he’s making secret wireless calls to other ships. Then, to make things worse, a single Cylon raider appears near the Galactica and begins acting strangely after being damaged in battle.
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
Tigh imposes martial law and threatens to split the fleet as Lee works to free President Roslin and organize democratic resistance.
Adama plans to return to New Caprica and drop off a surprising person to act as a liaison between Galactica and the Resistance. Tigh’s insistence on the use of suicide bombers and ever escalating violence stuns even the fellow leaders of the Resistance. Eventually, the suicide bombings cause the Cylon occupiers to crackdown on their human subjects.
When a new copy of Doral, a Cylon who had been previously exposed while serving as the Galactica’s public-relations officer, sneaks aboard and blows himself up, killing three people, Commander Adama and President Roslin must finally make public the terrifying secret known only to a select few: Cylons now look like humans.
Kara struggles with the foreboding prediction of the Cylon Hybrid, while Adama and the Colonial fleet face despair over their shocking discovery.
When President Roslin calls an Interim Quorum of the Twelve Colonies, she discovers that democracy brings its ugly stepsisters — politics and deadly intrigue — to the party. Tom Zarek, the charismatic convicted terrorist, is elected as the delegate from Sagittaron and immediately proposes elections for the vice-presidency.
When Baltar and the Number Six who lives in his head have a falling out, she abandons him, only to surface a short while later aboard the Galactica. But now she’s called Shelley Godfrey, everyone can see her, and she’s telling them that she has evidence, passed on by the late Dr. Amarak, that will prove Baltar sold out the human race to the Cylons.
A reporter is sent to Galactica to chronicle the harsh realities of life during wartime.
Adama and the Galactica crew stake the survival of the human race on their plan to rescue Hera from the Cylon colony in this, the series finale.
Tigh, Tyrol and Anders lead the Resistance on New Caprica to increasingly deadly attacks against the Cylons. Kara finds herself trapped in a new life with Leoben Conoy, and Duck makes a fateful decision. Meanwhile on Galactica, Adama struggles with the question of whether to return to New Caprica to mount a rescue attempt.
President Roslin faces off against Tom Zarek and Lt. Gaeta as they try to take control of the Colonial fleet. Both the alliance with the rebel Cylons and Adama’s life are at stake.
President Roslin faces challenges as the Colonials plot with Cylon rebels to destroy a Resurrection Hub.
The Battlestars Galactica and Pegasus face a new Cylon target, a “Resurrection” ship, while a power struggle threatens to result in all-out war among the human fleet.
Apollo assists in the search for a missing Raptor team as the new commander of the Pegasus grows increasingly unstable.
