The 2nd book in the Harper Jones series, following Torment (archived here):

It’s mid-summer. The oceanside town of Wolf Hollow is well into tourist season, with its glittering beaches and bustling boardwalk acting as the playgrounds of families celebrating their summer vacation. Detective Harper Jones has a new protégé to break in, Officer Mary Lou Perkins. Suddenly, over the course of a few days, local citizens begin to be randomly terrorized. But as the number of victims increases, Detective Jones starts to realize that they all have one particular thing in common. Him.

As the terror reaches closer to home, Harper’s discovers that the past consequences of Peregrine are clawing their way into his life today, and to stop them, he must confront an enemy that he thought he’d left far behind. From the sun-kissed boardwalks of Wolf Hollow to the Mediterranean lair of his tormentor, Harper must race to confront his nemesis before he’s forced to choose between his past and his present.