Jack breaks out of a locked down CTU so he can follow a lead from the key card. George Mason puts pressure on Jamie and Nina to learn of Jack's whereabouts. Palmer discovers who the source is that leaked the story about his son. Rick and Dan argue about how to handle Janet, while Teri and Alan run into an obstacle as they try to help their daughters.

The episode was rated 7.79 from 914 votes.

Keith takes matters into his own hands when he arranges a secret meeting with Carl. Elizabeth realizes who Alexis really is and immediately comes forward. Jack and Mason question her and then convince her to aid in his capture. The safe house is attacked, but Teri and Kim manage to escape. They are then separated by an unforeseen accident.

The episode was rated 7.78 from 709 votes.

Jack works to establish his cover with a small group of domestic terrorists. He learns that their target hits very close to home. Kim takes Megan and runs from the house, but Gary pursues them. Palmer and Eric disagree over how to deal with the media during the nuclear threat.

The episode was rated 7.78 from 661 votes.

Teri is struck with amnesia and must turn to an old friend for help. Kim goes to Rick's house in hopes of finding a lead. Jack sets Elizabeth up for a sting against Alexis, but she pulls a fast one at the last second.

The episode was rated 7.77 from 666 votes.

Jack takes drastic action to gain the cooperation of the only man who knows how to save Kim, but Mason's interference threatens to ruin Jack's advantage. Kim is delivered to Gaines and she learns just how ruthless he can be when he's crossed. Meanwhile, Teri and Alan watch over Janet in surgery. Palmer talks to the reporter who plans to break the story about Keith and she shows him proof to back up her claims.

The episode was rated 7.77 from 859 votes.

Jack and Chase quarrel over Chase's relationship with Kim. Meanwhile, they learn of a lead to the possible whereabouts of the virus after rading a crackhouse. Linda breaks up with Kyle when she learns that he is planning to make a drug delivery. Wayne approaches Palmer with information about his girlfriend that could damage his chances for reelection, while a CTU employee is not what he seems.

The episode was rated 7.77 from 512 votes.

It is California Presidential Primary Day in Los Angeles and the longest day of Federal Agent Jack Bauer's life is about to begin. Jack has just patched his family back together after a trying separation. Midnight finds Jack playing chess with his teenage daughter Kim. As she goes to bed, Jack gets a call from Nina Myers, his coworker at the Los Angeles Counter Terrorist Unit, telling him to come in for an emergency meeting. Jack has no choice but to report in, but he and his wife Teri learn that Kim has snuck out before he leaves. Kim and her friend Janet York drive to an empty furniture store where they party with a couple of college guys whom they recently met. Kim enjoys herself at first, but starts to become suspicious of the two men when they won't take her home. At CTU, Jack learns that an assassination attempt is being planned against Senator David Palmer; the first African-American presidential candidate with a serious shot at the White House. Jack's boss and friend, Richard Walsh, warns him that people in their own agency may be working with those who plan to kill Palmer. Senator David Palmer is making his plans for Primary Day when he receives a strange phone call that puts him in a bad mood. Jack shows how far he's willing to go to do his job when he blackmails District Director George Mason in the hopes of learning information about the Palmer hit. Teri receives a call from Janet's father, Alan York, and the two decide to go out looking for the girls. A European photographer makes pleasant conversation with a beautiful woman on a plane bound for LA. The two end up in a lustful encounter, but more sinister plans come to light that involve a stolen wallet and the destruction of the airplane.

The episode was rated 7.77 from 1469 votes.

A plot to assassinate the President of the Islamic Republic at the UN building comes to Jack Bauer's attention.

The episode was rated 7.77 from 465 votes.

Three years have passed since the events of Day Two. A van deposits a dead body outside the LA Health Unit. The body is infected with a deadly virus. Tony, now in charge of CTU, learns that this is a blackmail tactic to get the US government to release a drug lord, Ramon Salazar, whom Jack has just brought down, before Salazar's brother releases the virus into LA. Jack and his new partner, Chase Edmunds, prepare to sign a deal with Salazar at the prison. Salazar delivers a mysterious warning to Jack before killing his lawyer. Palmer is alive and well, and has returned to LA for the first time since the attack three years ago. He is running for re-election and is preparing for an important debate with a rival senator. He is accompanied by his brother, who happens to be his chief of staff and his doctor, who also happens to be his girlfriend. A young boy, Kyle Singer, is seen examining a large, mysterious bag of white powder. He plans to deliver it to some dealers later that day, but he is being watched by Salazar's men. Kim now works at CTU and has been dating Chase for three months. Kim wants to tell her father, but Jack has a mysterious health problem that may make things more complicated.

The episode was rated 7.76 from 546 votes.

Nadia approves an interrogation technique that might prove fatal to Audrey. Doyle covertly aids Jack in the hopes that he can save her from further mental trauma.Daniels discovers that he may have a leak in his administration when he is confronted by the angry Russian president.Chloe and Morris's relationship hits the rocks, while Heller delivers Jack a stern warning.

The episode was rated 7.71 from 368 votes.