The characters, Andrew, Marie, Duffy, Aunt Elise, and Andrew's mom are all on their way to go camping at an old house.
They arrive at the house, which is old, dirty and only a few lights work in it. the characters are all nervous to be staying at the house already when they find a message on the wall, "Beware the sentinel."
Beware the Sentinel
The kids and their moms take a walk in the woods and on their way back to the house Duffy leaves his jacket in the woods.
Later, the children's parents decide to go into town, leaving the children alone in the old house. After a while, Marie hears a scratching sound at the door. She warns the others and they start to become nervous.
Duffy looks out the window and sees something big. The kids get more scared then ever and head out to the barn to get away from the creature. They soon notice the creature is coming after them, so they return to the house and ascend into the attic.
Andrew looks out the window and sees the creature standing in the eerie moonlight with Duffy's jacket in its hand. The kids hear the thump, thump, thump as the creature climbs the stairs to the attic. Just then the door is thrown open, and the creature tosses Duffy's jacket into the room saying, "You left your jacket, stupid." It turns and isn't seen by the children again.