While Dr. Baltar is behind in the polls for the election and tries desperately to turn things around, Starbuck is planning a mission to rescue Anders from Caprica.

The Cylons have now been in control of New Caprica for over four months. Gaius Baltar is under their collective thumbs and essentially follows their orders. There is a resistance who set off bombs and do their best to disrupt Cylon activity. Col. Tigh is in prison and despite extensive torture, including the loss of an eye, has told them nothing. His wife Ellen will do anything to secure his release and is soon in a sexual relationship with one of the Cylons, John Cavil. There are mixed feelings among the survivors. Some feel the random acts of violence against their captors serves no useful purpose while others feel it is their duty to resist. Kara Thrace, Starbuck, is being kept prisoner in an apartment of sorts by Leoben Conoy. She too resists but every time she kills him, he is simply re-generated and reappears insisting he will continue to do so until he tells her she loves him. Back on Galactica, Admiral Adama takes his son Lee, Commander of the Battlestar Pegasus, to task for going soft.

As a result of the most recent suicide bombings, some of the Cylons are now arguing that they need to retaliate. Laura Roslin, among others, is in custody and Gaius Baltar tries to get her to cooperate. Tigh however absolutely refuses to stop the suicide bombings. Nighttime raids also leads to Cally's arrest but they leave her baby alone. Sharon Valerii sees what she can do about it. John Cavil meanwhile tells Ellen Tigh she is to provide the date and location of the next meeting of the resistance commanders. Leoben Conoy is still holding Starbuck prisoner but introduces her to her daughter, Kacey, produced from eggs they harvested from her when she was on the Farm. On Galactica, Admiral Adama begins to plan for a massive rescue of everyone on New Caprica. He realizes they will have to obtain the launch keys for all of the ships on the planet's surface. The best way of infiltrating the Cylons is with another Cylon so Adama commissions Sharon Agathon as an officer.

When a group of refugees board Galactica with a curable illness, it becomes very mysterious when they begin to die after taking the injection they do not believe in.

When the head of the fuel production plant holds the fleet hostage by providing unsafe fuel, he's arrested for treason, which results in the Chief sent to the ship and held responsible for getting the plant back up and running.

Besides having to deal with the loss of Kara Thrace, the crew of the Galactica is also charged with the security surrounding the trial of Dr. Baltar and his defense attorney, who is replacing one lawyer that has already been killed.

Baltar goes on trial for his life, and it affects everyone from Lee on up to the president.

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.

A shaky alliance between the Colonial Fleet and Cylon rebels is put to the test when the two groups combine efforts to take out a Cylon "Resurrection Hub". Meanwhile, Athena loses control when Hera becomes unnaturally drawn to Natalie.

President Roslin's abduction by the Cylon Hybrid triggers a bitter power struggle within the Colonial Fleet.

The Fleet refuses to cooperate with Cylon engineers and Adama decides to put an end to it. He sends the Quorum a message stating that unless they wish to join Zarek in the cell, they get their people in line. However, Gaeta has already freed Zarek with the help of other would-be-revolutionists. They allow Zarek to leave Galactica on a raptor. He lands on Colonial One and enters a gathering of the Quorum. Meanwhile, Anders gets ambushed and captured. At the CIC, Gaeta cleverly manipulates everyone else until the time is at hand for the revolution to begin.

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.