Years after a zombie apocalypse has decimated the globe, humanity clings to survival in a fortified city. The city is a stark dichotomy of wealth and poverty, where the rich live in luxury in a towering skyscraper called Fiddler’s Green, while the poor struggle for survival on the streets, surrounded by electrified fences and a vast river. Ruled by a ruthless businessman, the city's safety relies on the efforts of mercenaries and scavengers who venture into zombie-infested territories to retrieve food and supplies.

Outside the city's relative safety, the zombies are evolving, showing signs of complex thought and social structure, led by a particularly intelligent zombie. This development poses a new threat to the city's fragile peace. Inside, discontent grows among the city's lower class, who are tired of the inequality and harsh living conditions. Meanwhile, a group of mercenaries, including a savvy and ambitious man disillusioned with the city’s elitism and an independent-minded woman, embark on a critical mission outside the walls. Their actions inadvertently ignite a series of events that could either lead to the city's salvation or its ultimate downfall, as external and internal threats converge.