After a flight deck accident kills 13 pilots and wounds many others, Kara is thrust into service as a flight instructor and ordered to turn a group of civilian pilots and academy washouts into full-fledged Viper pilots.

Jack initiates a fierce gun battle with the terrorists as he races to rescue Heller and Audrey before the military strike begins.

Dina questions her own dedication to their cause when her husband reveals his plans for Behrooz.

Driscoll and Curtis uncover new evidence that points to an even bigger attack by the terrorists.

Audrey has an awkward meeting with her husband, and Heller butts heads once again with his son.

Major Sheppard plays a dangerous game of cat and mouse with soldiers who have seized control of Atlantis and taken Weir and McKay hostage.

A duplicate of Colonel Carter seeks help from Stargate Command in defeating the Replicator Fifth, who she claims has found a way to counter the Asgard’s new weapon.

Jack and Driscoll agree to work together when the police make a critical error in dealing with Kalil.

Heller and Audrey take drastic action in the hopes of avoiding the impending trial.

Driscoll makes a deal with Chloe to get her out of the way, while the Araz family faces another problem in their cover-up.

Lt. Sharon Valerii wakes up soaking wet in the tool room with an explosive charge in her duffel bag. Shortly afterward, a mysterious explosion destroys all the port-side water tanks on Galactica, creating a crisis for the entire fleet. Sharon can’t remember a thing, but all the evidence points to her as a saboteur. She confesses her concern to Chief Tyrol, but he can’t believe she’s responsible.

In the wake of the Cylon sneak attack, the ragtag fleet of human survivors is forced to play a deadly game of cat-and-mouse with their pursuers. Every 33 minutes, they make a jump to a new location. And every 33 minutes, the Cylons manage to find them. The pilots are on the brink of exhaustion, relying on artificial stimulants to keep fighting, and the civilians are beginning to doubt the leadership of Commander Adama and President Roslin.

Jack tracks Kalil with Chloe’s aid, but is forced to watch helplessly as Andrew is tortured for information.

Behrooz pleads with his parents when they order him to bring Debbie to their home for questioning.

Curtis uses harsh methods to interrogate Heller’s son as Driscoll continues to search for Jack.

Jack acts as a bandit and takes hostages to buy Chloe more time to get satellite surveillance. Meanwhile, Chloe must confide in Edgar for help when Driscoll becomes suspicious.

Behrooz discovers just how far his mother is willing to go to insure that their secret mission is successful.

Heller and Audrey attempt to escape from Omar, while Driscoll uses her influence to deal with a personal crisis.

Eighteen months have elapsed since the conclusion of Day 3. A commuter train bound for Los Angeles explodes. A man steals a suitcase from a passenger in the wreckage and then kills him.

Jack has been dismissed from CTU and now works for Secretary of Defense James Heller. Jack is involved with Heller’s daughter, Audrey, and their relationship is growing serious. Jack is in LA for a meeting with CTU Director Erin Driscoll, who fired him a year ago, but he finds himself alienated at CTU by Driscoll and the new staff when reports of a possible terrorist strike come in.

A young computer hacker named Andrew Paige sees something that he shouldn’t on the Internet. Suddenly, he finds himself running for his life as he is pursued by terrorists. Luckily, he is able to warn Chloe O’Brian before its too late.

The Turkish Araz family are not what they seem and it becomes clear that they are heavily involved with the day’s events. Meanwhile, Heller has a confrontation with his estranged son.

Jack finds that Chloe is his only ally as he tries to prove that the train explosion is merely a diversionary target.