Harlan Coben's The Woods (UK)

Paul “Cope” Copeland, whose sister Camille vanished from a summer camp, a loss that tore his family apart. Now a top barrister and devoted single father to 10-year-old daughter Cami, Cope appears to have rebuilt his life. But when the body of a man turns up — 20 years after he was supposedly murdered alongside Camille — Cope becomes convinced his sister may have made it out of the woods alive too. Determined to uncover the truth, Cope reunites with his first love, Lucy Silverfield, and together they begin a search for answers, unearthing years of lies, cover-ups and family secrets that threaten to destroy everything he has built.