Tabula Rasa by Shelly Reuben

A tragic house fire puts arson investigator Billy Nightingale and state trooper Sebastian Bly on the trail of an unusual killer. While investigating the clues at the fire scene – and taking care of the mysterious baby who survived – they discover a dangerous and determined arsonist. But despite her new family’s efforts to protect her, the young survivor must confront her horrifying past in a chilling showdown with a murderous mother determined to finish what she started.