Reading someone's diary is bad but Slappy is already evil, so how could anyone resist finding out all of this dummy's terrifying secrets? Zoey and Billy Traister find a large suitcase in a trash pile in the empty lot behind their house. Inside: a grinning ventriloquist dummy. Who would throw out a perfectly good dummy?
They bring it home and quickly find out why the dummy was tossed in the trash. They read the secret words and bring Slappy to life, who treats them to an evening of true horror; trashes their house; insults them; hurts them; orders them to become his servants.
The Traister kids grab him and struggle to force him back into his case. They carry the case back to the empty lot and heave it onto the trash pile. When they return home, they discover something fell out of the case - a diary. Slappy's diary.