When it comes to possession-themed books, William Peter Blatty wrote the ultimate, hands down, with "The Exorcist". In "The Girl in the Basement", Garton tackles the topic, adding his own ideas and giving the topic his own twists. It is hard to avoid mentioning the parallels between "The Girl in the Basement" and "The Exorcist". But, if you are going to imitate something, why not the best?
I share some of the same thoughts as other reviews who wished this book was longer.