As Sterling Cooper prepares for its 40th anniversary party, the bosses in London drop a bombshell to Lane. Miss Farrell's troubled brother pays a visit to her and Don, and Betty stumbles onto her husband's secrets.

Starring:

Aaron Staton, Alison Brie, Christina Hendricks, Elisabeth Moss, January Jones, Jared Harris, John Slattery, Jon Hamm, Kiernan Shipka, Robert Morse, Vincent Kartheiser

Genre:

Drama