Duffy, Marie, Aunt Elise, Mom, and Andrew are all heading to a cabin in the woods for a camping trip.
They went back and started poking around the house, which really was enormous.That was when things started getting a little spooky. In the room next to theirs, they found a messagescrawled on the wall. BEWARE THE SENTINEL, it said in big black letters.
They go on a walk through the woods and Duffy forgets his jacket and they feel like someone is watching them.
Sentinel says, "You forgot your jacket, stupid." Throws jacket at Duffy and walks away.
While the moms went to town to pick up supplies the kids were playing monopoly until they heard scratching. They thought maybe it was the person they thought was following them in the woods scratching. Then, Duffy went to look out the door to prove there was nothing out there. He saw something, so they ran out to the barn to hide but it was locked with a padlock.
They tried to hide in the bedroom, then when they looked outside they saw the sentinel holding Duffy's jacket, so they got even more scared. They saw it coming back and heard a bunch of thump, thump, thumps.
The sentinel went into the bedroom and gave Duffy his jacket back. Which is why, I suppose, no one has had to remind Duffy to remember his jacket, or his glasses,or his math book, for at least a year now.After all, when you leave stuff lying around, you never can be sure just who might bring it back.