During a seemingly hopeless battle, Kara Thrace appears in a pristine Viper, claiming that she has been to Earth and can lead the Fleet there -- but the terminal Laura Roslin believes otherwise. Meanwhile, four of the so-called Final Five are forced to tackle the repercussions of their newfound nature, while Gaius Baltar discovers he has a commune of nubile female cultists who believe him to be an agent of the "one true God".

The aftermath of a coup among the Cylons leads to further violence, Lee finds himself facing off against Roslin during his first meeting with the Quorum of Twelve as the new representative of Caprica, and Cally discovers the horrible truth about her husband Galen Tyrol. Meanwhile, Starbuck aimlessly searches for Earth with Anders and other Galactica officers.

Gaius Baltar causes intense unrest within the fleet when he begins to openly promote belief in the Cylon god. Colonel Tigh, Galen Tyrol, and Tory Foster argue over how far they should go to ensure their secret is not revealed.

When a Heavy-Raider manned by Leoben Conoy docks aboard the Demetrius, confrontations form between the crew over the possibility of a truce with Cylon rebels, while Starbuck puts her trust in an old enemy.

With Hera now likely in the hands of John Cavil, Admiral Adama sends out search teams to locate The Colony, the Cylon home world if you will, that Ellen Tigh says is the only place she imagines she could be. Adama reluctantly comes to the conclusion that the Galactica has reached the end of its days. He orders all repair activities halted and decides to strip the ship and share everything that is salvageable with the rest of the fleet. Starbuck meanwhile shares with Gaius Baltar what she found on the uninhabitable Earth. He subsequently - and quite publicly - proclaims her to be an angel.

The Colony is located sitting on the edge of a black hole with only one point of entry in what is a very large debris field. Knowing that the Galactica has reached the end of the line, Admiral Adama asks for volunteers to mount a raid on the Cylon base, realizing it may be the ship's last jump. In flashbacks prior to the Cylon invasion, key moments in the lives of several of the crew are presented. These include include the first time Kara Thrace and Lee Adama meet; Admiral Adama's struggle with his decision to retire from the colonial fleet; Gaius Baltar's relationship with his father and his developing relationship with Caprica Six; and Sam Anders discussing the motivation behind his professional sports career.

A stripped down Galactica attacks the Cylon's Colony ship in the hopes of rescuing Hera. The meaning of the shared dream in the Opera House on Kobol is revealed. Sam Anders is moved in his Hybrid tank to the CIC in the hopes that he will be able to assist the combatants. Their mission complete, Admiral Adama orders Starbuck to pick a destination - any destination - to which the ship can jump to get out of there. With that, the meaning of the tune and the musical notes are explained. Having successfully jumped, the old Galactica has truly reached the end of it's life. A planet capable of sustaining life is found and Lee Adama makes a radical proposal for the future of humankind. In a flash forward far into the future, Hera's importance to the human race is revealed.