The Last Death of the Year by Sophie Hannah

New Year's Eve, 1932. Hercule Poirot and his good friend Inspector Edward Catchpool arrive on the Greek island of Lamperos for a little holiday...or is it? Catchpool suspects Poirot has a different reason for being there — one he won't reveal. As the clock ticks towards the New Year and a festive guessing game takes a sinister turn, can Poirot stop a murderer who is determined to strike before midnight?