Under the streets of New York is a darkish and harmful world hidden within the shadows of deserted subway tunnels and miles of forgotten infrastructure. When a younger documentary filmmaker goes into these tunnels to uncover the unseen tales of the individuals residing under our toes, she finds out that there's extra to be afraid of than the darkish. A mysterious determine, residing past the attain of the legislation, has declared warfare on the skin world that threatens to tear aside the delicate underground society residing within the tunnels and possibly even the town above it.