Shadow

Mia Baxter has never known what a real nightmare is...
It's a week till school starts and a week after her dad cheated on her mom, resulting in a disastrous and rushed divorce. It's not that Mia cares about that...but when her ex-dad gets promoted and becomes her mom's new boss, her mom can't take anymore. That night she announces they're moving to a house her uncle left her in his will.
Two days later, her mom is driving Mia and her baby brother, Jeffery, fourteen hours to the small town of Berkshire, Vermont. Almost immediately, Jeffery starts some strange behaviour, and Mia is stuck with no friends for the entire summer. To make matters worse, her mom is never around anymore, almost as if she's disappeared.
This is not a typical teen-adjustment story. Now it gets ugly...
After two weeks of eerie silence, Jeffery erupts into tears on the kitchen counter. Mia rushes in. Standing over her brother, eyes gaunt and cheeks hollow, is the cursed ghost named Isaiah...
Terrified, Mia slowly starts to reach for a knife, but instead comes face to face with the grotesque demon Lidra. She is sure she's going to die when Isaiah leaps in front of her and vanquishes the demon back to the forbidden attic.
Isaiah explains that he was cursed to remain on Earth for eternity, denied his access to heaven. He wandered around for centuries before discovered the murderous spirits and demons that dwell in this house. He soon devoted his life (death?) to protecting the innocents that lived in the haunted house.
He also has a warning...Lidra and the other monsters are after Mia and Jeffery. They've waited centuries for a young, susceptible body to use as a passage away from the house and back to Earth. Mia and her brother and the perfect hosts for the demons to wreak their havoc. However, Mia's spirit cannot dwell in the body still...she must be killed.
Isaiah quickly becomes Mia's sole friend, protecting her and Jeffery from the demons that want her dead.
It is day-to-day terror for Mia, until her stepsister Lizzy comes to visit for the summer. Suddenly, all the ghosts disappear, including Isaiah. At first, Mia is relieved. Aside from missing Isaiah, she and her brother are finally safe. Even if Lizzy is cruel and she officially has no friends...
Oh, but it's not over yet. Just wait and see what happens next...
Soon, however, Mia begins to suspect something more sinister with the disappearance of the ghosts. Her mom stops leaving voicemails and stops leaving her shoes at the door...all traces of her disappear. Mia's fears are confirmed when she catches Lizzy hanging over Jeffery's crib, knife in hand...
Suddenly it's again a fight to stay alive, and this time, Isaiah cannot save her.