When Isabel Gallagher is found murdered on the floor of her baby's nursery by her mother, it's a gruelling case for Detective Lottie Parker.

Isabel's pyjamas have been ripped, her throat cut and an old-fashioned razor blade placed in her hand. As Lottie looks at the round blue eyes and perfect chubby cheeks of Isabel's baby daughter, she can't understand who would want to hurt this innocent family. That very same day she receives a call with devastating news.

Another young mother, Joyce Breslin, has gone missing, and her four-year-old son Evan has been abducted from daycare. Lottie is sure that the missing mother and son are linked to Isabel's death, and when she finds a bloody razor blade in their house, her worst fears are confirmed. Desperate to find little Evan, Lottie leaves no stone unturned as she delves into Isabel and Joyce's pasts and when she realises the two women have been meeting in secret, she knows she must find out why.

But when Joyce's body is found in a murky pond and some little bones are found on a windy hillside, it feels as if this merciless killer will stop at nothing. The bones aren't Evan's but can they give Lottie the final clue to find the innocent child before more lives are taken?