Eighteen months after faking his own death Jack Bauer is forced to return to Los Angeles when it becomes apparent that the only four people who know he is still alive are being systemically targeted for assassination. The assassinations coincide with the signing of an anti-terrorism treaty between Russia and the U.S., leading Jack to suspect a link between the assassinations, the treaty, and a group of Russian terrorists holding hostages at Ontario airport. But a shocking and deadly discovery at the airport reveals just how far the terrorists are willing to go and how thoroughly tested the newly signed treaty will be before the day is over.