On a cold dark night in February, as a blizzard shrieks through Cedar Valley, police officer and new mother Gemma Monroe responds to an anonymous report of a prowler at the local private high school, The Valley Academy. In her idyllic Colorado small town, Gemma expects the call was just a prank by a bored teenager. But there in the snow lies the savaged body of a man whose presence in town was meant to be a secret. And a disturbing message left by his killer promises more death to come.