In the mid-1980s, a county waterworks inspector is sent to survey storm-damaged culverts in rural Ohio. While tracing the flow through a network of inlets and old railroad cuts, he discovers an unmarked tunnel the locals quietly avoid. At first it seems like nothing more than outdated infrastructure, but fresh claw marks carved into limestone and eerie silences in the woods suggest something far more dangerous.  

As he and his crew return after dark to run tests, the sense of being watched becomes undeniable. Growls echo from the tunnel, stones are placed with deliberate force, and the creature within makes its presence felt without showing itself. The investigation culminates at a remote pump house, where all doubt is stripped away — the men finally come face to face with a towering, wolf-like figure whose roar shakes the cinder blocks around them. The encounter leaves them shaken and forever certain that some places in the backwoods are claimed and meant to be left alone.