Don is troubled by a letter; Peggy may seek a new future on a risky venture; Roger receives a phone call; Pete and Cutler butt heads.

Cast: Jon Hamm, Elisabeth Moss, Vincent Kartheiser, January Jones, Christina Hendricks, Aaron Staton, Rich Sommer, Kiernan Shipka, Jessica Paré, Kevin Rahm, Christopher Stanley, Jay R. Ferguson, Ben Feldman, Mason Vale Cotton, Robert Morse