What '80s book started the satanic panic?

By 1980, Disco was dead, Manson was behind bars, and America was ready for a new Boogeyman. So when a Canadian woman appeared on the talk show circuit with her bestselling book about wild tales of secret Satanic cults, American audiences were ready to dive into what would come to be known as the satanic panic. What book turned teenage metalheads and daycare workers into America's Most Wanted?