The thin line that separates humanity from the rapidly evolving Cylons is redrawn as Starbuck returns from the dead with claims that she has found planet Earth.

Conflicts flare among the Cylons as they confront the taboo mystery of the Final Five and Kara Thrace is pushed too far when her former friends and comrades refuse to believe that she has been to Earth.

With Kara Thrace piloting a lone freighter in her desperate search for Earth, political intrigue and marital discord aboard Galactica is matched by deep rifts in Cylon solidarity.

Baltar's beliefs create a controversy for those faithful to the 12 Lords of Kobol, and a crew member's demise casts a pall on the Colonials.

The search for Earth produces tension aboard the Demetrius for Kara and her crew mates.

Unlikely alliances are forged after the search for Earth takes an unexpected turn

President Roslin's leadership is tested as Galactica teams with Cylon rebels in a plot to destroy the enemy's Resurrection Hub.

President Roslin's abduction by the Cylon Hybrid triggers a bitter power struggle in the colonial fleet.

In pursuit of the enemy's Resurrection Hub, a misfit team of Viper pilots and Cylon rebels become uneasy collaborators in formulating a battleplan.

A band of rebel Cylons hold President Roslin hostage while attempting to lure the Final Five out of hiding aboard Galactica.

After the startling revelations of the mid-season cliffhanger, the fleet and its Cylon allies have united in a joint search for Earth. They encounter a devastated world where their expectations are shattered by events that echo down the millennia. Kara "Starbuck" Thrace (Katee Sackhoff) learns that the dire predictions of the Ancient Hybrid (of "Razor") may be true about her.

Adama believes that Cylon technology is the only way to save the fleet, but his proposal for an alliance meets fierce resistance, led by Tom Zarek.

The opposition to the alliance with the Cylons turns violent, as gun shots echo through the ships and those who support the alliance find themselves under attack.

Rebels take control of Galactica and take steps to eliminate Roslin and Adama.

On the Cylon baseship, Cavil confronts the last member of the Final Five.

As Galactica continues to deteriorate, Ellen is faced with a decision that could have repercussions for the Final Five, the humans and the future of the Cylon race.

Tyrol is thrown into crisis when Boomer is charged with treason; Kara strikes up a friendship with a charismatic piano player in Joe's bar who helps her face a shattering realization about her destiny.

As Galactica continues to deteriorate, Adama resists the need to abandon ship while Baltar meanwhile emerges as an unlikely voice of hope.

As the Galactica is stripped for parts, a call for volunteers is made for a final mission.

The conflict is at its climax. The Cylons and the humans face a difficult decision.

As conflicts reach a climax, Cylons and humans face a stark choice.