During the Prohibition Era, where trading with alcohol was illegal, the mafia is ruling the city. Don Falcone is entering the city to carry through his own rules and oppress the people. A special unit of the police around Edward Nash is sent to stop the crimes of the mob. A rough war is breaking out between rivaling gangs and between the FBI and the mob. You can choose whether to play as the police or on the side of the mafia. When you play on the mafia side, you are attempting murders, are kidnapping people and try to take control over the city. When you choose to play the police campaign it's the other way around: You try to free the city quarter after quarter and you have to solve several missions like investigations.