After handing in his detective badge, Mason Black now lives a stable life as a private investigator. But when the bodies of two children are discovered with messages written in blood, the pattern of a familiar killer emerges.
Now, the Carter twins are missing, and only Mason can help. With his unique knowledge of the killer, he has an advantage over the San Francisco Police Department. While his marriage falls apart, he must choose between repairing his life or opening doors that were meant to stay closed. There's just one problem; neither solution will restore his faith in humanity.
The Lullaby Killer is on the hunt, and Mason Black is always a step behind. As the trail reveals shocking secrets and surprising twists, you'll be holding your breath for the entirety of this gut-wrenching detective thriller.