Five high school seniors were going to the 'haunted house' when their car wouldn't start. Mike Rawlins who is a sophomore and works at his dad's auto shop stopped by and got the car going for them. They convince Mike to go with them to the haunted house and he does, but not before stopping and getting holy water at the church and buying salt. Mike had been there before, he knew to be prepared.Once in the house the girls are less than enthused. Talk about creepy. Mike makes a circle with the salt and holy water. The others think he's really nuts. Jerry and Stan are excited and Mike? Well Mike's been here before and he's less than enthused. The guys then head for the cellar. The cellar that has a huge stinking sinkhole and a metal hatch. The guys try to pull the hatch up only to have it fly up on its own.It releases a luminescent wave that goes through the entire house and crashes into their salt circle. This thing is screeching with rage and loud enough for the teens to grab their ears in agony. They all jump into the circle. The circle that is their only protection from this thing.Enter an emaciated mixed breed dog. The dog dives right through the apparition, jaws ripping at thin air. The dog then begins herding the apparition as though it were a sheep. Snapping and growling without fear until inexplicably the monster disappears. They all make tracks out of that house as fast as they can.Mike takes possession of the dog. A dog he names Demon. Demon is an Australian Shepherd/Lab mix. At least that's what the vet comes up with. Demon turns out to be Mikes best friend and as we go along Mike realizes that Demon is way more than just a dog. Mike and his friends who now have a bond are on a roller-coaster of a ride.