Hush — Adam Nicholls

"It started with a bloody corpse." Two years ago, Mason Black was a detective, a husband, and a father... until obsession with a killer drove him further from his family. That life was left behind, until today. Now a part-time PI, a familiar string of murders is pulling him back into the cycle. Mason must choose between bringing the killer to justice or remaining a humble family man. With his marriage on the line, the police seek his knowledge of the unsolved case, to help identify and track down the psychopath. But now he's too close to the Lullaby Killer, who is driven to have a little fun... at Mason's expense.