'I can't take my eyes off the water. Can you?' It's summer when Elm Hill lido opens, having stood empty for years. For Natalie Steele — wife, mother, teacher — it offers freedom from the tightly controlled routines of work and family. Especially when it leads her to Lara Channing, a charismatic former actress with a lavish bohemian lifestyle, who seems all too happy to invite Natalie into her elite circle. Soon Natalie is spending long days at the pool, socializing with new friends and basking in a popularity she didn't know she'd been missing. Real life, and the person she used to be, begins to feel very far away. But is such a change in fortunes too good to be true? Why are dark memories of a summer long ago now threatening to surface? And, without realizing, could Natalie have been swept dangerously out of her depth?