Set in Washington, DC, "Day 7" opens four years after Season Six with CTU dismantled and Bauer on trial. Bauer's day takes an unexpected turn when former colleague Tony Almeida (Carlos Bernard) returns. Meanwhile, newly elected President Allison Taylor (Cherry Jones) leads the country alongside White House Chief of Staff Ethan Canin (Bob Gunton) and First Gentleman Henry Taylor (Colm Feore).
A national security crisis prompts Renee Walker (Annie Wersching), Larry Moss (Jeffrey Nordling) and Sean Hillinger (Rhys Coiro). Although CTU is no longer, Chloe OBrian (Mary Lynn Rajskub) and Bill Buchanan (James Morrison) are back for another momentous day of shocking events.