Five Little Pigs // Murder in Retrospect — Agatha Christie

Poirot Perplexed

Hercule Poirot had never faced a problem as thorny as this one. He had to find out who savagely hated a man whose work the world loved. He had to prove the innocence of a woman already convicted of murder. He had to make sense of a collection of clues that seemed to point in every direction at once.

So far, it was the kind of case Poirot was used to. But there was one added complication:
THE CRIME HAD TAKEN PLACE SIXTEEN YEARS BEFORE--AND TO SOLVE IT POIROT HAD TO GO BEYOND THE GRAVE....