The novel centers on a group of American military wives stationed with their husbands at an Air Force base in England during the 1950s. It follows their lives, friendships, and the challenges they face as they navigate cultural differences, personal dreams, and the shifting social landscape of the 20th century. Despite the varied paths their lives take over the years, the women share a bond that endures through love affairs, family strife, and societal changes, capturing the essence of an era and the enduring power of friendship.

The novel centers around a woman named Amber who unexpectedly arrives and disrupts the lives of the Smart family while they are on summer holiday in Norfolk. Each family member - Eve, a writer, Michael, a university professor, and their children Astrid and Magnus - experience unique interactions with Amber, causing them to question their own realities. The mysterious woman's influence forces the family to confront their secrets, insecurities, and the false narratives they've created about themselves.