Seven days. Three families. One killer.

It was supposed to be the perfect holiday, dreamed up by Kate as the ideal way to turn 40: four best friends and their husbands and children in a luxurious villa under the blazing sunshine of Provence.

But there is trouble in paradise. Kate suspects that her husband is having an affair, and that the other woman is one of her best friends.

One of these women is willing to sacrifice years of friendship and destroy her family. But which one? As Kate closes in on the truth in the stifling Mediterranean heat, she realises too late that the stakes are far higher than she ever imagined.

Because someone in the villa is prepared to kill to keep their secret hidden.