Don't Forget Me

When Danielle and her family move into their new house, she doesn't know that her annoying younger brother Peter hears voices calling in the basement. And she thinks his acting like he has trouble remembering simple things while their parents are away is just a joke after she tries "hypnotizing" him to turn him nicer. But when he continues to do it, and she starts forgetting things too, she wonders if something else is going on. All she knows is, when she finds everyone denying they know about him and he appears from the cracks in the basement floor covered in slime with a bunch of other kids, that they may both be in danger.