Season synopsis
Contains spoilers for this season and earlier seasons.
With Adama gravely wounded by Sharon’s gunshot, Colonel Saul Tigh takes command of Galactica and declares martial law while Roslin is jailed. Tigh’s crackdown and a massacre aboard the civilian ship Gideon split the fleet; Roslin escapes and gathers ships to follow her religious claim that Kobol holds a route to Earth. Adama later joins the expedition, and the uneasy factions reunite at the Tomb of Athena. On Caprica, Starbuck and Helo meet human resistance fighters, escape a Cylon breeding facility, and return to Galactica with Sharon, who is pregnant with Helo’s child. Her presence makes Helo a target of suspicion.
A Cylon virus infects Galactica’s systems and lets Centurions board the ship. Tyrol’s crew builds the stealth fighter Blackbird, while a rescue mission to Kobol and the arrival of the surviving battlestar Pegasus bring new resources and a new command crisis. Admiral Helena Cain’s harsh rule collides with Adama’s, and both crews nearly turn their guns on each other. They instead join forces to destroy a Cylon Resurrection Ship, stopping the Cylons from restoring destroyed humanoid agents. Gina, the abused Cylon prisoner aboard Pegasus, escapes and kills Cain. Baltar saves the dying Roslin with an infusion of Sharon’s fetal blood. Sharon later gives birth to Hera, her human-Cylon daughter with Helo.
As a presidential election approaches, Baltar campaigns to settle a newly discovered planet he names New Caprica. Roslin fears the Cylons may find it, but she and her allies rig the vote; when the fraud is exposed, she cedes the presidency to Baltar. A nuclear blast destroys Cloud Nine and other ships, yet the fleet establishes the settlement. A year later, the Cylons arrive; Galactica and Pegasus flee, and Baltar surrenders the colonists. Starbuck vows resistance under occupation.