'Duchess of Death' by Richard Hack

Agatha Christie, history's bestselling novelist, always had a special relationship with Christmas. When she was a child, it was the occasion of happy memories before and after the turn of the 20th century. Once she became a prolific and popular author, the holiday was a marketing hook for her English publisher, who for decades urged customers to give "a Christie for Christmas."

And it was at Christmastime in 1926 that Christie lived through the most dramatic episode of her life: an 11-day disappearance that made headlines throughout Britain, had thousands of citizens seeking her whereabouts and -- after the wayward writer was found in a resort hotel in northern England, registered under the same last name as her then-husband's new love interest -- was brushed aside as "memory loss" and never publicly explained.

Richard Hack makes the most of Christie's sensational disappearance in "Duchess of Death," an "unauthorized biography" said to draw "from over 5,000 unpublished letters, notes, and documents." He devotes some 50 pages to a vivid re-creation of the author's movements and, by his creative reckoning, her motives in fleeing: Prompted by husband Archibald's demand for a divorce, she carried out a planned itinerary as elaborate as any of her timetable-pegged murder mysteries. It was a romantic scheme meant to provoke her disaffected spouse to "rescue" her and return them both to the sanctuary of a once happy marriage.

Fair-play plotter that she was, Christie (whose most recent book at the time of her vanishing was the notoriously innovative "The Murder of Roger Ackroyd") left clues to her destination in notes to her husband and her secretary, and in a letter mailed after she'd left. But circumstances conspired to prevent those hints from being heeded.

The chief impediment was the obtuse behavior of a supervising police inspector whose wrong-headed deductions would have tried the patience of even Christie's diplomatic fictional sleuth, Hercule Poirot. This real-life detective, his actions documented daily in newspapers Christie was reading, persisted in combing the countryside around the author's home in Surrey rather than the Yorkshire district at which she'd taken pains to point.

"Yorkshire, you idiot!" a hotel maid heard the still-in-hiding novelist shout one day in frustration.