Elk Ridge, Washington teeters on the brink of a supernatural collapse. To save her future, Liz must return to a past that she has abandoned, and face a monster that might swallow her whole.
Liz didn't think life could get worse after an injury cost her a college track career. That is, until her mom got a terrible phone call. Now, instead of training this summer, Liz is moving to the lonely coastal town of Elk Ridge to care for her sick grandmother's home. But returning to Elk Ridge means facing the friends she abandoned after her parents' nasty divorce, and the guilt that has chased her ever since.
The isolation of the coast soon gives way to something more unsettling. Already stretched thin by re-igniting old friendships and finding new plans for college, and navigating a deeply complicated relationship with her mother, Liz starts having strange dreams. A silver fox leads her through a forest that shouldn't exist, warning her that a monster is rotting Elk Ridge from the inside out. Something is poisoning a "mirror world" that sits like the reverse side of a coin against Liz's own. Liz wants to dismiss these dreams as stress-induced, but it becomes hard when she starts noticing fresh mud on her floorboards and tufts of silver fur on the windowsill.
To find the truth, Liz must reconcile with her old friends Theo, Phoebe, and Carter. Together, they uncover a terrifying connection between the wolf-like monster that has been stalking Liz through the shadows, and the charismatic new mayoral candidate whose new "economic revitalization plan" is stripping locals of their homes and livelihoods. As the four of them dig deeper into the corruption, Liz begins to realize that old feelings for Theo may not be as buried as she thought. As the moon reaches its zenith, the barrier between worlds thins. Liz must decide what she's willing to sacrifice in order to stop the corruption of Elk Ridge — because the monster in the woods is growing stronger, and it has already started hunting her friends.