Schoolteacher Calista Moore and her husband, Kirk, live in a charming suburban Massachusetts home with their son, Devon. Remi Toussaint, who owns a Florida yoga studio and gym with her husband, Gabe, has been hesitant to attend the reunion, but Gabe, who attended the same high school, encourages her to go. Avery Williams lives on an Iowa farm with her husband and children. Despite their encouragement, her life now appears vastly different from those of her friends. Mori Hart, the final member of the group and arguably the most successful, is an author and friend of the wealthy and famous. Along with her Martha’s Vineyard residence, she enjoys the use of a friend’s Cape Cod beach house gratis. On the arrival of everyone but Calista, the others chat about their lives over the past two decades. Meanwhile, Calista reaches out to Gabe, a lifelong friend, insists that he fly up to meet her at Boston’s Logan Airport, and then reveals that Devon is his son. At the same time, on the Cape, numerous glasses of wine encourage further startling revelations. Remi discloses that she’s pregnant with another man’s child. She and Gabe want a child of their own, but an accident has left Gabe sterile. Against the advice of her publisher, Mori decides to write a true-crime book, while Avery is gradually losing her sight. When Calista fails to show up, the friends grow increasingly anxious, and the police become suspicious of Gabe. When Calista’s body is discovered on the beach, the friends realize that their unique knowledge might well solve the case.
