a fugue you say?...

Young Agatha

Agatha Christie- MurderMysteries.com:

"Emotionally stung by an unexpected request for a divorce from her husband, Archibald Christie, Agatha disappeared for several days in 1926 and the newspapers of the era had a field day investigating the mystery surrounding where Christie could be. Not only had her husband astounded her by telling her that he was in love with another woman, Agatha had recently been devastated by the death of her beloved mother. She drove off in her Morris motor car and it was later found crashed in Yorkshire. For 11 days she was not seen by a living soul. It was later discovered that she was staying in a hotel in Harrogate in Northern England under an assumed name to escape what must have been a horrible emotional shock for her. The complete details of where she spent those 11 days have never been uncovered and Christie herself refused to talk about the incident or respond to any questions about whether she suffered from a case of amnesia or depression. A fictionalized account of this mysterious incident was dramatized in the 1979 film, Agatha, starring Dustin Hoffman and Vanessa Redgrave."

The Observer- Christie's most famous mystery solved at last:
"In his study of the writer's life published this autumn, Norman uses medical case studies to show that Christie was in the grip of a rare but increasingly acknowledged mental condition known as a 'fugue state', or a period of out-of-body amnesia induced by stress. In effect, the writer was in a kind of trance for several days, he claims.

via Boing Boing