Crocodiles in the sewers, snakes in the plumbing, giant spiders coming out of manhole covers... all urban myths.

Except in Megalopolis. Lieutenant Jericho, a disgraced and disillusioned police officer, is guiding Sandra Yeatman, a student of zoology, through the gleaming new sewer tunnels and the crumbling old ones in search of creatures that should not exist. In the city beneath the city, they find a terrifying infestation that threatens the lives of all who dare to go... under.