Lower-level cabinet member Tom Kirkman becomes President of the United States after a catastrophic attack on the U.S. Capitol. Kirkman must keep the country and his family safe while leading the search for the those responsible for the attack.

President Kirkman fears there could be a traitor in the White House when he discovers shocking information connected to the Capitol Bombing. Confiding in Emily, Kirkman puts her in charge of quietly investigating. New information surfaces about Congressman MacLeish, raising concerns regarding his vice presidential nomination.

An investigative journalist shocks the White House when he reveals classified information during a press briefing and leaves Seth struggling to contain the damage from the leaked story. Hannah unearths a key connection between MacLeish and the conspiracy.

Turmoil in an African country forces President Kirkman to rely on an unlikely ally for help. Hannah's investigation into the Capitol bombing takes an unexpected turn. Emily settles into her role as chief of staff. Aaron has to make a difficult choice.