The Good Demon by Jimmy Cajoleas

She knows she's possessed by a demon but she's like having a sister.  She's good company, tells her stories, and she enjoys having her around.  At least she does until she takes possession of her...

Amulet Books sent me a copy of this book to read for review (thank you).  It is being published today.

When she almost gets raped, the demon takes over and bites the boy badly.  Her stepfather has a preacher in to get rid of the demon.  She feels lost and alone and wants her demon back.  What she doesn't realize is the cost she will have to pay...

This is a horror story where the girl learns about demons and herself.  What she thought she was willing to do, she's not.  She has to learn to stand up for herself.  This isn't a story you will forget quickly...