Fact based urban horror film Parasites to play the New York City Horror Film Festival From Chad Ferrin, the man who gave you the trippy shocker Someone’s Knocking at the Door comes Parasites, an innovative urban horror thriller that takes the true tale of folk hero John Colter. Synopsis: The industrial barbarism of downtown Los Angeles is equal parts player and punisher in this survive-at-all-costs tale of a group of friends who get lost in the seedy streets, where they encounter a crazed gang of homeless derelicts who seize them and, one by one, horrifically kill all but one man.