When Park Ranger Zoe Watts finds a man beaten within an inch of his life on an otherwise peaceful, suburban trail, she's in uncharted waters- especially considering all the peculiar activity in the woods lately. Happenings that point toward something wicked. Something more myth than human.

As Zoe digs, she comes up empty. Every person who hikes, bikes, or runs through the park is suddenly a possible suspect. Shrugged off by her fellow rangers, Zoe secretly teams up with the crime-fighting team of PI Casper Kelly and Delaney Shepard (and of course their trusty pup Hoagie), fresh off solving the case of the Punkhorns.

But the further Casper and the team dig, the muddier the truth appears. Before long, it's clear that Casper is up against his toughest case yet.

With more twists than a switchback up a mountain, buckle up. Be prepared. There is trouble afoot...