In a remote Northwoods cabin, a chilling phone call triggers a race against time as a serial killer's past collides with a present that threatens the lives of those closest to him....

When a body is discovered on Flag Mountain, a series of cryptic messages lead Detective Liu to a chilling revelation about the killer's past and the enigmatic call that brought him to the mountain....

A young doctor in a secluded sanatorium uncovers a series of mysterious deaths, leading to a harrowing revelation about the past and a shocking twist involving a silent call....