Successful beauty entrepreneur Vivi Savidge is about to celebrate her fortieth birthday at the Palazzo Stellina, a historic former convent in the foothills of the Italian Alps.

Vivi's little sister is flying in from Brisbane with her sixteen-year-old twins in tow. Her ex-colleague and his new husband are coming from Boston, and old university friend Caroline is driving from Turin. Every one of them is hiding a shameful secret.

Amid a suffocating heatwave, the holiday ignites an explosive cocktail of obsession, jealousy, and greed. Before the week is over, secrets will be exposed and the gathering will turn deadly, leaving one victim, a handful of suspects, and a murderer in their midst.