Computer game company founders Grace MacBride and Annie Belinsky—along with Wisconsin deputy Sharon Mueller—are en route to Green Bay, following reports of a serial killer, when their car breaks down deep in the northern woods. A short walk through the forest leads them to the eerily quiet town of Four Corners, where they find severed phone lines and a complete absence of any life. But the quiet is deceptive. Before they know it, they witness a horrifying double murder—and discover that this is only the beginning of a race to save their own lives…and countless others.