Season 4 · 24 episodes
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 S…
Jack pushes Driscoll to reinstate him in the wake of Heller's kidnapping. He finds himself working as a subordinate when the Field Ops team goes to pick up Andrew. Behrooz finds himself torn between his loyalty to his parents and his feel…
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 in…
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 …
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 …
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 a…
Jack takes Audrey to ID the man she recognized at the compound, but the terrorists get there soon after and pin them down. Jack must call on an old friend to help him escape. Heller puts Edgar in charge of dealing with the nuclear overrid…
Jack and Audrey hide out with an embittered Tony as Audrey makes a positive ID of the man from the kidnapping. Marianne successfully diverts suspicion from herself, leading Driscoll to torture the wrong person for information. Behrooz ta…
Jack and Tony are able to trace Dina's location, but Behrooz slips through their fingers. Dina demands a full pardon for her son in exchange for information on the override device. Edgar wrestles with his emotions when his mother is trapp…
Audrey places herself in a compromising position when she and Jack learn of her husband's possible involvement with the terrorists. Marianne offers Curtis information on the location of the override device in exchange for a lighter senten…
Jack and Curtis finally learn the location of the override device. They try to trap the architect of the terrorist strike before the remaining nuclear plants go critical. Tony pushes Dina to reveal more of her knowledge of Marwan, while D…
Jack and Paul visit the defense contractor who employed Marwan, but the company executives put their own interests ahead of CTU's and take major steps to destroy evidence. After a grief-stricken Driscoll relinquishes her command, Heller a…
Jack and Paul enlist civilian help when they must fight off soldiers sent to kill them by McLennan-Forster. Tensions flair between Tony and Michelle as she assumes command of CTU. Sarah tests Michelle's authority by giving her an ultimatu…
Jack learns the identity of a man who may be able to lead him to Marwan. He forces Dina to help him in a mock hostage situation that will get him close to the suspect. Michelle calls on Chloe for help when Edgar begins to crack under pres…
Marwan decides to trade Jack for Behrooz in hopes of distracting CTU from his real objective. Tony and Michelle weigh the consequences of the trade, while Curtis reluctantly interrogates Behrooz in order to learn more about Marwan.
CTU raids Marwan's hideout, but he manages to slip through their fingers. Luckily, Jack locates a lead that may help him identify Marwan's next target. Tony becomes suspicious of Michelle's personal life, while Audrey reunites with Paul a…
Mike pushes for the Vice-President to be sworn into office as the White House waits for news of Keeler's fate. Two innocent bystanders are dragged into the fight as Jack and Marwan both pursue a briefcase that contains the launch codes fo…
Curtis brings in a suspect who has critical information about Marwan's next strike. Michelle orders Curtis to use harsh methods to interrogate the suspect, but things get complicated when Marwan sends a lawyer to defend his rights. Logan'…
Chloe is unexpectedly thrust into fieldwork when a woman reports that her boyfriend may be part of the terrorist conspiracy. Jack and Curtis find their latest efforts to trap Marwan thwarted by the Secret Service, who have orders to arres…
After Logan authorizes Palmer to take charge of the crisis, Palmer sanctions Jack and Curtis to infiltrate the Chinese Embassy on a covert operation to capture a suspect. Tony and Michelle continue to bump into each other's personal lives…
CTU scrambles to forge an alibi when a Chinese representative produces evidence of American involvement in the raid on their embassy. Audrey gives Jack the cold shoulder, while Palmer and Logan clash over the consequences of Palmer's deci…
Jack finds that his efforts to bargain with Marwan for the location of the missile strike are futile. Heller pushes his son for information when CTU discovers that he may have had contact with Marwan before the attacks. Logan finds himse…
Mandy uses Tony as leverage to try to force Michelle to aid in her escape. A Chinese security operative captures and interrogates one of the CTU agents involved in the raid on the embassy. Palmer and Logan argue over the option of evacua…
As the missile speeds toward its destination, Mandy cuts a deal with Jack and the President to give up Marwan's location in exchange for a full pardon on all of her crimes. Tony and Michelle share a happy reunion, but Jack finds his relat…