Grady Hendrix has done it again. A couple of years ago, I fell hard for Horrorstör, a horror tale set in an IKEA-like retail store, and I’ve been waiting anxiously for his follow-up novel ever since. My Best Friend’s Exorcism has much of the same type of horror/humor mash-up that I loved in Horrorstör, with the addition of a heartwarming story about a life-long friendship. Even better, for those of us who fondly remember the 80s, Hendrix takes us back in time to the era of cassette tapes, big hair, the AIDS scare and many more iconic 80s moments.  But don’t let that fool you. This is a horror story with some very creepy and unsettling moments. Hendrix has toned down the over-the-top crazy horror in his first book and given us a much subtler terror this time around, the kind that ratchets up slowly until the suspense is nearly killing you. The story is set in 1988 and mostly takes place at a small private high school in Charleston, SC. Abby and her three closest friends—Gretchen, Margaret and Glee—are sophomores at Albemarle Academy, and life is pretty much status quo. Their lives are full of school work, boys, the latest…