Michelle Ogborn's The Witch's Pentacle

A girl named Silly (Sylvia) goes to an old burnt, run down house with her friends and finds a knife that shoots her mind back over torturing endings of different lives that she lived. She has to fight all over again and again. The demons reappear as soon as the visions end and she now has to battle. They collect up her family and torture them to get Silly to do what they want her to do. The knife being her only protection to survive she guards her family and herself with it. She tells the story in a voice over with the begining showing her in the present day still fighting them.