Russian President Suvarov is set to meet President Logan to sign an arms treaty when David Palmer is assassinated, Tony Almeida and Michelle Dessler are hit by a car bomb and someone starts chasing Chloe O'Brian. The only link between the four of them is that they are the only people who know that former CTU agent Jack Bauer is alive. Written by Shiro

CTU uncovers evidence that seemingly links Jack Bauer to the assassination of David Palmer. In a bid to clear his name, Jack enlists the help of Chloe O'Brian as they head to Wayne Palmer's apartment, the site of the assassination, to see what evidence they can find. Meanwhile, Walt Cummings looks in to the phone call Martha Logan received from David Palmer the night before and a terrorist group continues to set their plans for the day in to motion. Written by Shiro

Jack Bauer takes up a tactical position in the Terminal that the Terrorist group has taken over. As he feeds information to CTU about them, the Terrorists state their demands on live television. Meanwhile, Martha Logan tries to find unaltered evidence of her phone conversation with David Palmer the night before. Written by Shiro

Jack Bauer is captured by the terrorists who threaten to kill Derek if he doesn't feed CTU false information. There's a race against time as CTU must plan and execute their assault on the terminal before Presidents Logan and Suvarov sign the treaty, which will signal the execution of the hostages. Back at CTU, Lynn McGill, arrives from District to observe CTU's dealings with Jack Bauer on behalf of the White House. Written by Shiro

Jack Bauer is taken in to custody at CTU, but the terrorists admit that he remains a threat to their plans, tasking their man inside CTU to take him out. Despite her being attacked, President Logan refuses to believe what Martha is trying to tell him about David Palmer's phone call. President Logan asks Walt to make the arrangements to have her re-admitted to a psychiatric hospital. Meanwhile, Curtis makes some progress in investigating the mysterious canisters the terrorists took from the airport. Written by Shiro

Jack Bauer arranges to meet with Mike Novick after discovering that Walt Cummings is involved in the terrorist plot. Pre-empting this, Walt reveals his involvement and the true nature of the plot to President Logan. The nerve gas arrives at the port, ready for its trip to Moscow as CTU continues its investigation, still under the assumption that it is to be used against Americans. Written by Shiro

President Logan convinces Jack to accept reinstatement to CTU following the revelation that Erwich plans to use the nerve gas on Americans. CTU gets a lead on one of Erwich's associates who is helping him re-configure the detonation codes on the canisters. Meanwhile, President Logan enlists the help of his wife, Martha, as an advisor and replacement for Walt Cummings. Written by Shiro

Posing as Rossler, Jack goes under cover with the terrorists in the hope that they will lead him to Erwich, even at the expense of hundreds of lives in a shopping mall. Meanwhile, President Logan, Martha Logan and Mike Novick debate how best to deal with the suicide of Walt Cummings. Written by Shiro

Jack Bauer is contacted by James Nathanson, the man who sold the nerve gas to the terrorists. The terrorists are trying to kill Nathanson and he offers Jack information on their whereabouts in exchange for protection. The terrorists contact President Logan, threatening to release the remaining nerve gas on US soil if he does not give them details of the route of President Suvarov's motorcade, allowing them to plan an assassination. Meanwhile, Lynn McGill becomes increasingly paranoid that people at CTU are working against him. Written by Shiro

President Logan discovers that his wife, Martha, has joined the Suvarov's in the car. The Terrorists will set off the 19 canisters of nerve gas if Logan stops the motorcade and saves his wife, stopping them from assassinating President Suvarov. Meanwhile, Jack heads to Omicron International to meet Christopher Henderson, a former colleague from CTU. Meanwhile, Lynn McGill loses grip on his command at CTU. Written by Shiro

Tony Almeida regains consciousness and learns of Michelle's death. President Logan deals with the aftermath of the attack on the Suvarovs' motorcade. As Jack attempts to track down Christopher Henderson, CTU discovers that the terrorists are planning to release a canister of the nerve gas in a hospital within the hour. Written by Shiro

Christopher Henderson is taken in to CTU to be interrogated as one of the terrorists infiltrates the building using Lynn McGill's stolen key card. Kim Bauer is reunited with her father, Jack, but struggles to deal with the fact that he is alive. Meanwhile, the Vice President arrives to assist President Logan with handling the crisis. Written by Shiro

CTU goes in to lock-down following the nerve gas attack. The gas remains a threat to the survivors as it breaks away seals protecting safe zones in the building. The terrorists begin to move towards their next target as Vice President Hal Gardner tries to convince President Logan to declare martial law in the city of Los Angeles. Written by Shiro

Homeland Security moves in to CTU as they move on Collette Stenger in a bid to get to Bierko. President Logan announces Martial Law in the Greater Los Angeles area. Wayne Palmer travels to meet with Aaron Pierce to talk about his brother, David Palmer. Written by Shiro

Audrey Raines is taken in to custody at CTU after Collette Stenger revealed that Audrey had passed information to her. Chloe also uncovers evidence that Audrey may have been working with Walt Cummings. Bierko hijacks a police car, allowing him to move the nerve gas canisters to the Wilshire Gas Company without hindrance during the curfew. Aaron Pierce goes looking for Wayne Palmer after he failed to turn up to their meeting. Meanwhile, Shari Rothenberg replaces Edgar placing her under the authority of Miles Papazin, who she claimed sexually harassed her in a former job. Written by Shiro

With Bierko in custody, CTU makes Christopher Henderson their priority. The investigation is hindered by the take over of CTU by Homeland Security. Wayne Palmer reveals that Martha Logan's assistant, Evelyn, was in contact with David Palmer regarding the terrorist plot. However, she is unwilling to talk as the terrorists have kidnapped her eight-year-old daughter and have threatened to kill her if Evelyn reveals the evidence. Written by Shiro

After discovering that the main antagonist of the nerve gas operation is President Logan, Jack and Wayne learn that Evelyn Martin has proof that Logan is complicit in the form of a digital recording. To make things even more difficult for Jack, Logan issues a warrant for his arrest in order to prevent him from getting to the evidence. Homeland Security's Karen Hayes and Miles Papazian monitor both Audrey and Chloe to try and pick up a thread on Jack. Written by Anonymous

Audrey and Jack meet Secretary of Defense Heller at the airport to give the recording to him. Heller says that it is not the right move to take down the President, and that the President should step down quietly, and orders his men to secure Audrey and Jack. Meanwhile, Karen and Miles try to find a way to extract the information from Chloe about Audrey's whereabouts. They trace a call to the airport phone. James Heller phones Logan and tells him that he wants to meet with him regarding the recording. Mike Novick begins to be suspicious of Charles Logan when he learns that an order to the military for the apprehension of Jack Bauer never existed. Aaron Pierce tells Martha Logan to meet him outside of the Retreat to explain some things to her about the day's events, but when she goes there, she finds only his cell phone. Chloe escapes from CTU, and goes to Bill Buchanan's house to help Jack. Jack and Audrey escape from the airport shed where they were being held, but are soon met by ... Written by George Henry

Jack and Buchanan work outside the chain of command by recruiting Curtis for help. Homeland Director, Karen Hayes, begins to see discrepancies in the President's actions and begins to suspect his motives.

Jack gets Henderson, but finds that the recording has been handed off. He tracks down the recording to a diplomatic flight. Jack gets on board, takes out the Marshal, and tries to discover who has the recording. Bill Buchanan is taken into custody, but is working covertly with Karen Hayes to help Jack. Jack eventually discovers who has the recording: the co-pilot. Written by John Lincoln

When President Logan realizes he is backed into a corner, he resorts to a drastic solution. While Karen becomes an ally in Jack's quest to expose Logan, Miles changes allegiances, and a villain from the past returns.

Vladimir Bierko manages to escape custody and take control of a submarine, the Natalia, bent on getting his revenge against the US. Jack reluctantly teams up with Henderson in hopes of getting a lead on Bierko, while Martha helps Aaron.

Jack Bauer teams up with Christopher Henderson to put an end to Vladimir Bierko's terrorism.

Jack Bauer works with Martha Logan to get a confession out of President Logan and an old antagonist returns to settle a score with Jack.