

After being abducted and locked in a basement, a boy starts receiving calls on a disconnected phone from the killer's previous victims.

Two operatives are appointed to posts in guard towers on opposite sides of a classified gorge.

As Finn, now 17, struggles with life after his captivity, his sister begins receiving calls in her dreams from the black phone and seeing disturbing visions of three boys being stalked at a winter camp known as Alpine Lake.