In the gritty streets of 1970s Cleveland, Danny Greene, a tough Irish-American laborer and mob enforcer, rises through the ranks of the local crime scene. After a stint as the head of a corrupt union, Danny establishes his own operation, challenging the Italian mafia's dominance. His outward charm and ruthless tactics earn him notoriety and the nickname "The Celtic Warrior." As Danny builds his empire, he survives several assassination attempts, bolstering his reputation as an indestructible force. Despite the growing tension, he forms a shaky alliance with Shondor Birns, a powerful Jewish mobster, and further cements his control.

Tensions boil over as Danny's defiance against the mafia escalates into an all-out war, drawing the attention of law enforcement and fellow criminals alike. His bold and brazen actions disrupt the city's underworld, leading to a series of violent confrontations. The FBI steps in, monitoring Danny and the increasingly volatile situation. As betrayals mount and alliances crumble, the stakes grow higher. Every move Danny makes sends ripples through the crime-laden community, pushing everyone towards an inevitable and explosive conclusion.