A man named Brody sits in a passenger train as it moves through a remote part of the Santa Clarita Valley. A titanium briefcase is handcuffed to his wrist. He has two guards to protect him. Suddenly, the train brakes as it smashes into an old truck filled with metal drums that ignite on the train's impact. A helmeted driver on a dirt bike approaches the train wreckage and heads straight for Brody, who is writhing on the ground. The driver, named Dar, shoots Brody. With bolt cutters, Dar pries the briefcase from Brody's wrist and speeds away.
At CTU in Los Angeles, Chloe O'Brian and Sarah Gavin look up someone from the FBI watch list that was spotted in the city. Tomas Sherak, a known Turkish terrorist, might be linked to a credible threat in the U.S., and the attack was scheduled for 8:00 am.
CTU head Erin Driscoll gets word about the train bomb. Chloe lets her know that it may be connected to Sherak's spotting and the potential threat. Chloe also questions Driscoll about an upcoming Defense Department meeting with Jack Bauer. Jack hasn't been to CTU since Driscoll fired him.
Jack dresses in a hotel room. He is with Audrey Heller Raines, who also dresses. Audrey asks if he will be uncomfortable returning to CTU, but Jack says it was his own decision to retire from the field. He kisses her. Audrey asks Jack not to tell her father that they are a couple. Both Audrey and Jack work for her father, Defense Secretary Heller.
Agent Curtis Manning briefs Driscoll, Chloe, Sarah and another techie named Edgar Stiles on the Sherak information. The assumption is that Sherak will try to leave Los Angeles after the train explosion. Chloe wonders if the bombing at 7 am does not correlate with the timing of Sherak's supposed terrorist attack at 8 am. Driscoll orders her to stay on course with Sherak's flight out of LA.
Tomas Sherak phones a man named Navi Araz at his home. Sherak brings news that Dar acquired the briefcase. After hanging up, Navi tells his wife Dina that he suspects their teenage son Behrooz may be dating an American girl whom they forbid him from seeing. Navi yells at Behrooz, who is angry that his father has read his emails. They all hear a television report of the train accident. Navi instructs Behrooz that he will take the briefcase from Sherak to a warehouse."What we accomplish today will change the world," Navi says."We are fortunate that our family has been chosen to do this."
A programmer named Melanie, enters the office of a graphic design startup and sees her co-worker, Andrew Paige, has been working through the night. As Andrew is stealing some software, he notices that there are nodes put in place that will corrupt the entire Internet. Andrew agrees to call the Feds to warn them -- but only from a payphone so he doesn't get caught stealing code.
Jack and Audrey come down to the hotel entrance and meet Secretary of Defense James Heller. Heller apprises Jack of the train bomb and asks him to find out more when he visits CTU.
Andrew Paige calls his friend Chloe to warn her about what he found on the web. Some of the damaging code is in an Arabic language.
Sarah digs up someone in Los Angeles with a dry cleaning business that is owned by a Turkish holding company. Chloe lets Driscoll know about Andrew's discovery. The server feeding the worm is based in Turkey, where Sherak is from. Driscoll tells her to pass that on to FBI so that she can focus on the bomb. Chloe is annoyed that her conclusions are dismissed so easily.
Jack enters CTU and notices the changes to the office. He greets Chloe, informing her that Kim and Chase are living together after he left CTU. Manning introduces Jack to Ronnie Lobell, the new head of field ops and Jack's replacement. As Jack waits for Driscoll, he sees the sense of urgency in the air.
Audrey rides with her father to her brother's house. Heller wants to convince his son Richard not to take part in a protest that might embarrass the President.
President John Keeler phones Heller to say he is considering raising the threat level based on the train bombing.
Jack meets with Driscoll about the Department of Defense's budget for CTU. He questions some of her proposals to increase monies, much to her chagrin. Driscoll excuses herself to watch feed from the field op agents who have visited the dry cleaning business owned by a Turkish company.
Jack watches the feed along with Driscoll. As Ronnie fruitlessly questions the man at the counter, Jack insists to Driscoll that the man is hiding something. Driscoll shakes off his claim. Jack points out that the man keeps looking suspiciously to his right. Driscoll radios Ronnie to warn him. The agents raid and grab the fleeing Sherak. Jack shakes his head. If it weren't for his help, they wouldn't have nabbed him.
With his Secret Service detail in tow, Heller arrives at Richard's house. He enters alone.
Meanwhile, Jack calls Audrey to warn her that CTU has captured their suspect in the train bombing. Jack also tells Audrey that he is falling in love with her. She is pleased. Jack cuts off when Driscoll returns to the office. He tries to get information from her on the suspect, but she won't reveal anything.
Despite his father's plea, Richard insists on participating in the protest rally. They argue.
Andrew returns to the office after calling Chloe from the payphone. He sees a man beating up Melanie and asking what she found on the Internet. Melanie names Andrew as the one who found something but that she doesn't know what it is. Andrew runs out and trips over a murdered co-worker. He jumps on his bike and speeds away before the hitmen spot him.
Driscoll gives Jack an open socket to look up the budget numbers. He sees Sherak being brought in by Ronnie. Jack tells Driscoll that he knows Sherak under the name Jann Bolek, who was traced to bombings in Europe in the nineties. Jack insists that something doesn't seem right. This guy wouldn't have risked coming into the country for a simple train bomb. Driscoll dismisses his advice again.
Jack turns to Chloe and asks whether there was any indication that there might be more than one attack. Chloe says that there was a time discrepancy, but that Driscoll thought the time was close enough. He pushes Chloe aside and logs onto her computer to Interpol. Jack looks at the intel and knows that Sherak didn't just come here for the train. Something will happen at 8 am.
Audrey phones her estranged husband Paul in a desire to proceed with the divorce. She is interrupted with a call from Jack who urgently needs to speak to Heller. He needs clearance to work on a possible second terrorist strike. Audrey goes into Richard's house to get her father.
Audrey comes in and hands the phone to Heller. She tells her brother that he is only trying to hurt their father.
Heller tells Jack that he is hesitant to step on Driscoll's toes and to let CTU handle it. Before Jack can press further, Heller hangs up in order to take a call from the President.
Jack sneaks into the interrogation room where Ronnie is ineffectively grilling Sherak. He takes down a guard in the process. When Ronnie steps out, Jack goes in with his gun raised. Driscoll yells at him over the intercom, but Jack proceeds to shoot Sherak in the leg, demanding to know what's going to happen at 8:00."What is your primary objective?" Jack screams. Sherak says it is the Secretary of Defense. Jack demands that Driscoll notify Secret Service immediately.
Jack calls Audrey's cell as she stands outside her brother's house with her father. He warns her that Heller is the real target. Suddenly, a rocket grenade sails past her face and hits a Secret Service vehicle, which bursts into a ball of flames. Jack hears the gunfire over the cell phone, as a van pulls up and gunmen fire at the Secret Service agents. Richard watches through his window in fear as masked men abduct Audrey and Heller into a van. Audrey screams for Jack, who can only listen helplessly.
Dar arrives at the Araz house and hands the briefcase to Navi. They embrace.