Postern Of Fate (agatha Christie Mystery Series)

When Tommy and Tuppence Beresford moved to a quiet English village, they were looking forward to a peaceful retirement. But, as they soon discovered, their rambling old house held both secrets and dangers. Who was Mary Jordan? Why had someone left a code message in an old book saying that she ‘did not die naturally’? And what was the significance of "Oxford" and "Cambridge"?<br>