Bobby loves his dog King, a playful German Shepherd - until the day King turns and attacks him, snarling and vicious. The dog is put to sleep but Bobby still sees him everywhere - in the garden, on the stairs...crouching...waiting...Then the horrific deaths begin - brutal savage maulings. Terror grips the sleepy town of Fallsburg and doors are locked at night. For through the woods runs a dark shadow with dripping jaws, eluding pursuit with uncanny skill. Now, more than ever, the scientists down the road most guard the deadly secret of the monster they've let loose.