Carl Brantley, Mac's nominee for Attorney General, takes a hit from the Senate during conformation hearings due to his actions towards crime, but Mac remains sure in her nominee. Meanwhile, a plane carrying weapons goes missing over Pakistan and Vice President Keaton takes charge of the situation using his military experience. Rod begins to settle into his role as First Gentleman, but when Kate goes missing, Rod, and the rest of the family, become panicked.
Mackenzie Allen, the 45-year old Independent Vice President, is about to enter a world in which no woman has ever stepped foot in before. While in attendance at a ceremony with her husband, Chief of Staff Rod Calloway, Mackenzie is given the startling news that President Bridges needs emergency brain surgery to treat a brain tumor. Mackenzie is given an additional shock when she is also informed that in the event the President doesn't make it through surgery, the party doesn't want her succeed him.
However, despite sexist insults from both the dying President and Speaker of the House Nathan Templeton, Mackenzie decides to fulfill her duty as Presidential successor and take her rightful place as Commander in Chief of the United States of America.