McGill returns to the CTU office shaken. Buchanan updates him on Rossler's death. Erwich calls Rossler's phone and Chloe records it.
Using an indistinct voice, Jack answers Rossler's phone. Erwich gives who he thinks is Rossler the location to meet one of his men. Curtis readies a tracking device inside the chip.
Jack calls Buchanan. Since Erwich is sending a man who does not know Rossler, Jack can pretend to be him. Even though this is risky, Jack knows that it's the only way to lead them to Erwich and the nerve gas.
Curtis shows Jack that the chip is genuine and can detonate the trigger. The chip also has a listening device so that CTU can hear what's happening.
Erwich instructs one of his men to come up with a backup plan in case the chip doesn't let them trigger the nerve gas by remote.
Novick suggests to Logan that they attribute Cummings' suicide to despondency instead of labeling him a traitor. Without Cummings to answer for what he has done, the President may be liable for his crimes. Logan notes that Martha will have a problem with this lie.
Evelyn asks the First Lady about Cummings' death. Martha is preparing a statement for the President that will lay out everything. Evelyn still questions whether Cummings really killed himself. Martha explains that he was a traitor.
Curtis watches as a blue van arrives to meet Jack at the rendezvous point. Edgar runs the plates and finds that the van has been stolen. Jack, acting as Rossler, approaches the two men and they show him the payment for the chip.
As Chloe instructs him over his earwig, Jack works on the trigger. He replaces the chip, but the men want him to accompany them to ensure that it works. CTU listens as one of the men, Polakov, punches Jack and throws him into the van.
Audrey insists that CTU stop this mission. Erwich knows who Jack is from the airport, and now he is in danger. McGill thinks this is the only solution for grabbing Erwich. Buchanan goes along with McGill, who orders Curtis not to interfere with the men capturing Jack.
Evelyn gives Martha the press release that the President has issued. It brands Cummings as a hero. Martha is furious and goes to Logan's office to find out what happened. Novick explains to her that Cummings' suicide would not allow him to face justice. Martha accuses Logan of serving his own self-interest instead of confessing to what really happened. The President suggests that she be the one to tell Cummings' wife the truth when the woman comes to collect her husband's body. Martha says that she will do the right thing, no matter how painful.
As Curtis follows the van, Jack tries to get information from Polakov. Jack realizes that they have one of the nerve gas canisters inside the van. McGill won't let Curtis intercept until they have a visual on the canister. Chloe tracks the van heading towards a shopping mall.
Chloe sends schematics of the mall to the tactical teams, who are getting into position. The men unload the canister and plan to walk through the front door. Jack refuses to go with them because there are hundreds of video cameras there and he only agreed to sell them the chip. Polakov forces him to follow. Audrey radios Jack that the tactical teams will recover the canister before they enter the mall.
Audrey is incredulous when McGill doesn't let the teams move in to grab the canister. He would rather accept the damage of one canister versus allowing the other nineteen to be released. Audrey tries appealing to Buchanan, who decides to call the President.
Jack and the two men dress as air conditioning repairmen and enter the mall.
CTU watches as Jack and the men are picked up on the mall surveillance cameras. They pass a children's birthday party as they enter the security guard area.
Polakov shoots a security guard. They pull out a blueprint and set about slicing open the air ducts.
Jack listens in as CTU gets the President on the line and explain the situation. The other nineteen canisters could be deployed in densely populated areas like sports arenas and subway systems. The loss of life would be great. This one canister would cause fewer casualties.
As Polakov and his accomplice place the canister into the duct, Logan weighs the options. McGill and Buchanan agree that the greater good would be served by releasing the gas in the mall, but Audrey believes they have no right to sanction the deaths of innocent people.
Logan does not want to decide but only he can legally make the call. Logan gives in to their assessment about releasing the gas in the mall in order to nab the terrorists with the other nineteen cans.
McGill gives Jack the go to follow the terrorists' plan. Jack and the men put on their gas masks. Buchanan gives Jack the unlock code, but Jack transmits the wrong code to Polakov. McGill orders him to provide the correct code, but Jack ignores this. The canisters do not arm, and Jack tells Polakov that there is nothing he can do to make it work.
Polakov calls Erwich and explains that they cannot arm the canisters. He doesn't know whether to believe "Rossler." Erwich says that they may have another way to detonate the canisters. The men knock out Jack and handcuff him to a table. CTU listens as Polakov discusses that there may be a way to release the gas without the remote trigger.
Jack wakes up and hears Polakov receiving instructions on how to manually open the valve on the canister.
Audrey argues with McGill about saving the children in the mall, but McGill stands by the President's command.
As Polakov nears completion of the detonation, they don their masks. The partner goes to kill Jack, but Jack kicks the man off his feet and takes his mask. Polakov flees, missing Jack's shots. Erwich hears the gunfire. Jack grabs the keys from the dead guard and releases his handcuff.
Jack goes to the air duct and stops the canister from releasing more gas. He alerts CTU that he prevented the flow, but that some nerve gas has seeped into the air conditioning system. They should evacuate the mall and find Polakov. Jack warns another security guard about the gas. The man radios for emergency procedures and an announcement is made over the PA.
As the shoppers run in panic, Jack looks for Polakov. People start dropping from inhalation of the gas. Jack finds the ventilation control room and shuts down the panels.
Jack sees a little girl lying restless on the ground. He puts his mask to her face and carries her outside to Curtis. Jack calls for a shot of atropine as the girl passes out. He injects her and she wakes up.
Chloe tracks the moving signal from the chip held by Polakov. Polakov breaks into a parked car and hotwires it. He peels out of the lot.
As he drives, Polakov calls Erwich and explains that "Rossler" tried to stop them. Erwich instructs him to come back to the auto shop.
While Chloe tracks Polakov, Jack and Curtis follow him. McGill calls the President to tell him that Jack disobeyed the order. Logan is furious.
Novick gives Logan word that a small amount of casualties were contained at the mall. CTU has a chance to find Erwich and the other canisters. He also adds that Suzanne Cummings has arrived at the retreat.
Suzanne Cummings cries to Martha, blaming herself that she wasn't with her husband when he died. Logan eavesdrops as Suzanne asks Martha why Cummings committed suicide. "Walt loved this country," is all Martha can answer. When she exits the room, Martha looks at Logan, disappointed.
Chloe tracks Polakov to an auto body shop. McGill gives the order to set up a perimeter and begin the team's approach. From a distance outside in a car, Erwich watches as the CTU teams surround the auto body shop.
Erwich calls Polakov, who is inside the shop. He tells him that he has been followed. "You know what to do," Erwich instructs. As Jack enters the building, Polakov shoots himself in the head. Both Erwich and the canisters are gone.
Erwich and his remaining men drive off in a pickup truck.