This is book number 23 in the Hercule Poirot Mysteries (Audio) series.
The classic Evil Under the Sun, one of the most famous of Agatha Christie's Poirot investigations, has the fastidious sleuth on the trail of the killer of a sun-bronzed beauty whose death brings some rather shocking secrets into the light.
The beautiful bronzed body of Arlena Stuart lay face down on the beach. But strangely, there was no sun and Arlena was not sunbathing...she had been strangled.
Ever since Arlena's arrival the air had been thick with sexual tension. Each of the guests had a motive to kill her, including Arlena's new husband. But Hercule Poirot suspects that this apparent "crime of passion" conceals something much more evil.