In 1926, famed mystery writer Agatha Christie (Williams) went missing for 11 days. She was found at a hotel and couldn't remember what had happened to her, although hypnosis revealed that Christie knew her husband Archie (Coulthard) was an unfaithful wastrel. But Christie also left clues in her writings and, in 1962, the aged Agatha (Massey) speaks of her disappearance to a journalist.