The FBI pulls Jack Bauer from a Senate hearing because an old pal of Jack's may be planning terror, while the President calls for military action in Africa.

A device that overrides the nation's homeland systems falls into enemy hands while the President's husband investigates his son's recent death.

Conspiracy may be deep within the President's administration, her dead son may not have killed himself, and a colleague Jack thought was dead has turned terrorist: how are these surprises related?

Bauer decides to trust two former CTU colleagues, and he helps a third escape from the FBI.

Jack helps terrorists kidnap a deposed prime minister while an FBI agent and the President's spouse are in grave danger.

The President defies murderous demands, while Jack and his CTU colleagues unearth an FBI Agent and plant a wire on a deposed Prime Minister. Who's in the conspiracy?

Jack and his patchwork team race to prevent an act of terror against a chemical plant; the President's husband and an African Prime Minister remain in danger.

Jack and an FBI agent believed dead have less than an hour to rescue the First Gentleman from certain death. Can they trust anyone?

The President rushes to the hospital as Dubaku plans an escape to Belize with Marika. The mole at the FBI keeps burrowing.

Moles within the U.S. government go to great lengths to protect their anonymity when they fear that Dubaku's list of corrupt employees will fall into FBI hands.

Intelligence suggests another attack is imminent, so Jack goes to the White House to interrogate a Senator's Chief of Staff.

General Juma's direct attack on the White House endangers the President, Jack, Bill Buchanan, and the President's daughter.

While the President is in danger and the Vice President vacillates, Jack and Bill try to counter Juma, realizing later that his plot is part of a larger threat.

Jack visits a U.S. Senator in pursuit of links between Juma and Starkwood, an international corporation. Security leaks at the FBI continue as they hunt for Jack.

While the FBI hunts for Jack, he and Tony Almeida search for biological weapons that Starkwood has smuggled into the U.S.

After Jack is exposed to a biological agent, Moss leads an FBI strike force onto the Starkwood compound in search of weapons of mass destruction.

Jack battles the effects of toxic exposure, a reporter squeezes the President's Chief of Staff, and it is a race against time to locate weapons on the Starkwood compound.

The President meets with Jonas Hodges while Jack battles toxins in his body and works with someone inside the Starkwood compound: can they destroy the bio-weapons before rockets rain death on U.S. cities?

As grief and loss begin to overwhelm Jack and those he is close to, a double-cross goes undetected, a canister of toxic gas is in enemy hands, and a surprise death occurs.

A shadowy group of powerful people decide to stage another attack as Jack rues trusting the wrong person, Jonas seeks asylum, and the CTU servers boot up.

Olivia wants revenge against Jonas, while Jack, Chloe, Janis, and Renee try to locate a young Arab who is being set up to take the fall for a new terrorist attack.

Jack and Renee pursue the final canister, which is on the Metro, ready to explode. Chloe and Janis match wits. Kim sits at the airport about to fly home, while a cover up begins at the White House.

Jack is abducted for nefarious purposes, Kim sits in danger at the airport, and Olivia matches wits with Ethan Kanin.

Jack seeks solace from a hospital bed, a shadowy traitor comes into the open, and President Taylor, Renee Walker, and Kim Bauer each have a decision to make.