While Jack has problems with Curtis, CTU discovers a nuclear threat and raids a terrorist warehouse, and a shocking explosion shakes LA.

To find the remaining suitcase bombs, both Jack and the President set up bluffs.

A new U.S. President has negotiated Jack's release from a Chinese prison so Jack can stop a series of terror attacks... with his life.

Can Jack and an unlikely ally stop a suicide bomber and track the architect of these acts of terror?

Jack rushes toward his nephew and his oldest antagonist, as a Chinese sub and F-18s race for the same destination. Chloe faints. Can Jack find any peace?

The search for Gredenko finds Jack hunted inside the Russian Consulate and a former President calling on his ex-wife.

Russian ire worries the White House, while the Chinese take on CTU, and the damaged circuit board is in surprising hands.

Jack and former terrorist leader turned peacemaker, Hamri Al-Assad, track a suspicious man to a self-storage facility.

Four more "suitcase nukes" are out there, and Jack's only lead takes him to the home of his brother.

Family troubles: Jack with his brother and father while Morris worries about his own brother.

The President meets with a known terrorist, while Jack searches for Morris, Fayed seeks a trigger, and Tom Lennox makes a choice.

Jack looks for a Russian national as his father plots with shadowy patriots. Meanwhile, the President and the Constitution may be in danger.

While Jack looks for Gredenko and tries to save Josh, White House intrigue deepens.

Jack's search takes him to the Russian Consulate, while the Vice President contemplates a sweeping executive order.

Jack baits Fayed with Gredenko, while the President faces a challenge to his office.

Jack's search takes him to the home of an old enemy, while a bomber slips into the White House.

CTU's satellite tracking system is compromised as a bomb-carrying drone heads toward an unknown city. Meanwhile, US forces prepare for a nuclear retaliation on the Middle East.

Jack enlists the help of an autistic man in the search for Gredenko, and Sandra Palmer makes a fateful decision.

Russia presses the White House, while Jack must try to thwart the Chinese and his oldest antagonist simultaneously.

In order to prevent a war with Russia, the White House orders a trade of Jack's nephew for the circuit board, and puts Jack in custody so he cannot stop the exchange.

Jack finds himself confronting his father while the lead terrorist needs help if he's to explode the remaining bombs.

The Chinese want Jack to give them Russian nuclear technology, and the President wants the Vice President's resignation.

Jack goes rogue to save a woman, and the White House needs a fall guy for Fayed's success.

A missing computer circuit board: the Russians get wind of Chinese espionage, the White House must find a leak, and CTU interrogates an unlikely witness.