What is the secret of Agatha Christie's unique appeal and what was the motivation behind her prodigious output? This program seeks clues to the elusive character of this enormously popular writer. The detective is Janet Morgan, who has written a biography of Christie. Among those providing evidence are P.D. James, Peter Saunders, Marghanita Laski, and Alexander Zinoviev. Archival film of Christie and her family provides the viewer with further insights, and excerpts from her books, plays, and films help to finish the puzzle.