As Thanksgiving approaches, Don’s work responsibilities interfere with his domestic life. Peggy is given a new opportunity, provoking the ire of some of her colleagues. Betty makes a startling discovery.

On election night, the Sterling Cooper staff pulls a rowdy all-nighter while watching the returns. Pete’s ambitions cause him to directly challenge Don. Don remembers his past as a soldier…

A rival ad agency courts Don, involving Betty in their attempt to lure him from Sterling Cooper. As the presidential campaign heats up, the agency looks for new ways to…