The sixth season is set 20 months after season five. Over the last 11 weeks before Day 6, the United States has been targeted coast-to-coast in a series of suicide bombings. A man named Abu Fayed agrees to give the U.S. the location of Hamri Al-Assad, the supposed terrorist mastermind of these attacks, in exchange for former CTU Agent Jack Bauer with whom he has a personal grudge. As a result, President Wayne Palmer has negotiated the release of Bauer, who was illegally captured by Chinese government agents, under "high-price" terms.
Season 6 can be divided into two main acts:
Jack is released from the Chinese prison, and works with CTU to take down suitcase nuke-armed terrorists, and discovers links to his own family in the process.
After the nukes are recovered, the Chinese manipulate Jack into giving them one of the circuit boards, elevating tensions between the United States and Russia.