Season synopsis
Contains spoilers for this season and earlier seasons.
Four months into the Cylon occupation of New Caprica, Saul Tigh and Galen Tyrol lead a resistance while Admiral Adama weighs a rescue with too few ships and pilots. The Cylons tighten their control, and Gaius Baltar signs an execution order under pressure. Adama commits Galactica to the assault as Lee and Pegasus guard the rest of the fleet. The rescue succeeds, but Pegasus is destroyed, Maya is killed, and the Cylons leave with Baltar. Back in the fleet, a secret tribunal executes suspected collaborators until Laura Roslin restores the presidency, abolishes the Circle and pardons those it targeted.
The fleet then faces a Cylon plague that invites Lee Adama to consider wiping out their enemy, a plan Helo refuses to let proceed. Food contamination forces the ships through a dangerous radiation field to reach an algae world, where Tyrol discovers an ancient temple and the Eye of Jupiter. Human and Cylon forces race to interpret it. Sharon Agathon retrieves Hera, while Number Three sees one of the hidden Final Five before the Cylons box her model and the planet is destroyed by a star going nova. The fleet resumes its search with Baltar back in Colonial custody.
As Baltar's treason trial begins, Romo Lampkin defends him and Lee leaves military service to challenge the case in court. Lee's appeal to judgment and forgiveness turns the proceedings, and Baltar is acquitted. Meanwhile, Tigh, Tyrol, Samuel Anders and Tory Foster hear a recurring melody and discover they are Cylons. The arriving Cylon force catches the fleet without power near the Ionian Nebula. During the standoff, Lee investigates a Viper contact and finds Kara Thrace alive after her apparent death in the gas giant's storm. She says she has found Earth and can lead them there.