The witch hunter

Detective Jessica Niemi is called to investigate a murder case which is completely out of the ordinary. The wife of a famous writer, Roger Koponen, appears to have been killed in a bizarre ritual. As more ritual murders occur in the coming days, it becomes obvious that Jessica is after a serial killer. But the murders are not random - they follow a pattern taken from Roger's bestselling trilogy. Has a devoted fan lost their mind, or is this case more personal?