In 1939 London, Miss Guinevere Pettigrew (played by Ms. McDormand) is a middle-aged governess who finds herself once again unfairly dismissed from her job. Without so much as severance pay, Miss Pettigrew realizes that she must - for the first time in two decades - seize the day. This she does, by intercepting an employment assignment outside of her comfort level - as "social secretary." Arriving at a penthouse apartment for the interview, Miss Pettigrew is catapulted into the glamorous world and dizzying social whirl of an American actress and singer, Delysia Lafosse (Ms. Adams). Together, the two will empower each other to discover their romantic destinies.