Invisible Terror Collection: The Guardian

At the start of the fifth book in Bill Myers' Forbidden Doors series, Becka Williams' best friend Julie is involved in a hit-and-run accident. When Julie awakes in the hospital, she's convinced an angelic being is caring for her and living inside her---but Becka is sure the spirit Julie has welcomed is anything but angelic. With Julie's spiritual wellbeing at stake, Becka risks everything to convince her friend of the truth.