Seatco, the invisible demonic spirit after which Spirit Lake on Mt. St. Helens is named, is released when a family of weekend hikers chisels off the guardian petroglyph entombing it in a hidden rocky gulley. Once freed, Seatco possesses the body of the grandfather and goes on a killing rampage. He reappears in Portland during the Rose Parade and leaves a trail of grisly murders making Lyle Robertson, the detective assigned to the case, wondering whether...