While traveling from London to Kingfisher Hill to discretely investigate murder allegations against a wealthy client's wife, Hercule Poirot swaps seats with a nervous train passenger before a second killing is complicated by a series of impossible confessions.

"What I intend to say to you will come as a shock ..." With these words, Lady Athelinda Playford -- one of the world's most beloved children's authors -- springs a surprise on the lawyer entrusted with her will. As guests arrive for a party at her Irish mansion, Lady Playford has decided to cut off her two children without a penny . . . and leave her vast fortune to someone else: an invalid who has only weeks to live. Among Lady Playford's visitors...