Scamming Death - The Scary Mary Series, #5

Gran is the most important person in Mary's life. Mary would do anything for her. So when Eddie, a freshman at her school, asks Mary for help with his grandma, she can't say no. But what he wants is an exorcism. Mary goes to meet his grandma with misgivings. She's not sure how she'll break the truth to Eddie. Elderly people can change. They can stop recognizing their loved ones. They can act like completely different people.
Alzheimer's can do that. Dementia can do that. But a ghost can do that as well. Eddie's grandma is possessed. But the ghost swears that she's protecting the elderly woman because there's something scarier than ghosts at the nursing home. An angel of death stalks the building. With Eddie and her friends, Mary must find the angel of death and stop them, but how do you stop an angel? Mary will have to figure that out before the angel strikes again.