Kelly’s new life in Philadelphia has turned into a nightmare: She’s friendless and jobless, and the lockdown has her trapped with the man she gave up everything for, who’s just called off their wedding. The only bright spot is her childhood friend Sabrina—now a glamorous bestselling author with a handsome, high-powered husband. When Sabrina and Nathan offer Kelly the spare room of their remote Virginia mansion, she jumps at the chance. One night, a wild and unexpected threesome leads the couple to open their marriage for her. At first, Kelly loves being part of this risqué new world. But when she discovers that the last woman they invited into their marriage is missing, she starts to wonder if they could be dangerous . . . and if she might be next.