Then She Was Gone - Lisa Jewell

Ellie Mack was the perfect daughter. She was fifteen, beloved by her parents, friends, and teachers. She and her boyfriend made a teenaged golden couple. She was days away from an idyllic summer vacation, with her whole life ahead of her.

And then she was gone.

Now, her mother, Laurel Mack, is trying to put her life back together. It's been ten years since her youngest child disappeared, seven years since her marriage ended, and only months since the last clue in Ellie's case was unearthed. So when she meets an unexpectedly charming man in a caf, no one is more surprised than Laurel at how quickly their flirtation develops into something deeper. Before she knows it, she's meeting Floyd's daughters--and his youngest, Poppy, takes Laurel's breath away.

Because looking at Poppy is like looking at Ellie.

Laurel is haunted by her long unanswered questions. What happened to Ellie? Did she run away from home, as the police have long suspected? Who is Floyd, really? And why does his daughter remind Laurel so viscerally of her own missing girl?