Dredd's investigation into the death of a seemingly unremarkable sewage worker spirals into a waste management crisis that could destroy all of Mega-City One, which has long used genetic modification on its waste workers to control the deluge of filth that flows under the city each day. When Dredd discovers that some of them have foregone that disfiguring procedure in favor of hosting protective alien symbiotes, it sparks a groundswell of anti-immigration fervor. Soon the toxic atmosphere spills into the streets, undermining the very infrastructure that makes the city tolerable. Can Dredd find a solution to save the now-indispensable aliens from the angry mobs?