Laura and Adama face the possibility that one of their ships has been infiltrated by the enemy.

Boomer worries that she is responsible for an explosion that causes Galactica to lose water.

Apollo is held hostage on a prisoner ship by a group of convicts led by a freedom fighter.

Starbuck is forced to admit her role in the death of Adama's son, Zak.

Adama and Lee put the fleet at risk while searching for Kara.

When a Cylon suicide bomber kills three, Adama must reveal to the public that Cylons now look human.

Baltar faces death and dishonor when a disguised Number Six accuses him of being a traitor.

When a Cylon is discovered on one of the ships, Adama sends Kara to interrogate the machine.

President Laura Roslin fears that Commander Adama might be a Cylon.

When fuel supplies dwindle, the fleet must make an attack on a Cylon-controlled tylium mine.

The return of democracy to the fleet.

A supply patrol discovers a hospitable planet.

As the fleet prepares to battle the Cylons, tensions between Adama and Laura explode.

With Adama wounded and Laura Roslin in the brig, Tigh faces his first test of leadership.

Tigh must work with Lee to defeat a Cylon boarding party that threatens to take over Galactica.

The return of democracy to the fleet brings hardball politics and potentially deadly intrigue.

Tigh's imposition of martial law threatens to split the fleet.

Adama returns to duty.

Adama wrestles with his son's betrayal; President Roslin puts her trust in a Cylon.

Adama launches a search mission.

A reporter is invited aboard Galactica.

Sharon's loyalties are questioned when a computer virus penetrates Galactica's operating systems.

The appearance of a superior colonial battlestar is cause for celebration aboard Galactica.

Teams try to join forces.

Battlestar Galactica and Pegasus battle to destroy the Cylon resurrection ship.

Roslin flashes back.

President Roslin tries to end black-market trading.

Galactica's Viper pilots are called upon to protect a Colonial mining operation.

A civilian holds military and government personnel hostage.

Battlestar Pegasus deals with internal crisis and external threat.

Number Six and Sharon become heroes of the Cylon.

Lay Down Your Burdens, Pt 1: The accidental discovery of a habitable planet swings the election in Baltar's favor, while Starbuck's rescue mission to Caprica runs into unexpected trouble. Edward James Olmos, Mary McDonnell.

Laura must choose between stealing the election and allowing Baltar to win.

Humans find various ways of living under Cylon rule on New Caprica; Adama plans a rescue mission.

The Cylons crack down on the humans after a bombing.

Adama prepares to rescue the human population on New Caprica.

Adama prepares to rescue the human population on New Caprica.

A secret jury forms aboard Galactica to pass judgment on those who collaborated with the Cylons.

A deadly virus forces the Cylons to make terrible choices to protect their race.

D'Anna tortures Baltar to find out who is responsible for the virus.

A pilot escapes from Cylon custody and returns to Galactica.

Memories haunt the crew.

The fleet faces starvation.

Stand off between the Cylons and the humans.

The Galactica team must race to find clues to the Earth's location.

Captors interrogate imprisoned ex-President Gaius Baltar aboard Galactica.

Galactica's medical team struggles to curb an epidemic triggered by Sagitarron refugees.

A pair of crew members are trapped outside in an airlock.

Chief Tyrol's labor leader persuades him to defy Adama and become the rallying point for a strike.

Kara Thrace is on the edge of a breakdown.

Sabotage, dissension and unlikely alliances cause complications.

As the trial of Gaius Baltar begins, testimony rivets the fleet's attention.

Coincidences creates new alliances aboard Galactica.

Lee Adama embarks on his first mission as commander of the Battlestar Pegasus.

Starbuck's mysterious return; Anders has a surprising standoff with a Cylon raider.

The Cylons confront the taboo mystery of the Final Five; Kara is pushed too far.

Political intrigue and marital discord-rifts in the Cylons' solidarity.

Baltar's beliefs become a controversy; a crew member's demise casts a pall on the Colonials.

Starbuck is inspired by the truce between humanity and rebel Cylons to trust her old enemy, Leoben.

Helo refuses to obey Starbuck's orders; President Roslin relies on her aide.

The Galactica helps destroy a vital enemy target, testing a new alliance.

A power struggle emerges when President Roslin is abducted by the Cylon Hybrid.

A team of Viper pilots and Cylon rebels formulate a battle plan.

The rebel Cylons hold President Roslin hostage.

The fleet and its Cylon allies unite in a search for Earth.

Adama's proposal for an alliance and a habitable space is met with fierce resistance.

Gaeta and Zarek execute a power grab the puts Adama and Tigh on the defensive.

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

Ellen Tigh resurfaces; Anders tells Kara that he remembers everything.

The survivors desperately search for the fabled 13th colony, Earth.

Thrace plays piano in a bar; Boomer faces extradition; Tyrol realizes Boomer tricked him.

The ship continues to deteriorate as repairs continue; Hera is delivered to Cavil.

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

Admiral Adama leads a group of volunteers into a dangerous mission to rescue Hera.

Events and conflicts reach their climax, and humans and Cylons face a stark decision.