Below the streets of New York lies a dark and dangerous world hidden in the shadows of abandoned subway tunnels and miles of forgotten infrastructure. When a young documentary filmmaker descends into these tunnels to uncover the untold stories of the people living there, she discovers that there is more to be afraid of than the dark. A mysterious figure living deep below the city beyond the reach of the law has declared a war on the outside world that threatens to tear apart this fragile underground society and maybe even the city above it.