Having no allies within the corrupt Cuban regime, Ness and his team get in touch with the Cuban rebels who are trying to overthrow the president and his government. If they succeed, Capone's plan to smuggle liquor from Cuba is D.O.A.
Chicago is put under martial law and a tough army general is sent to clean up the streets and destroy the mob. Ness doesn't like him or trust him and opposes his methods openly.
Ness is told that he's been in coma for a year. His family is gone, but his archenemy, Capone, is behind bars for good. Ness suspects something doesn't fit when he's asked about the whereabouts of one of his informers.
One of Ness' men, agent Malone, believes he knows who's behind the killings of German immigrants in Chicago. A German WWI spy and Malone's archenemy from the war is back in town.
Ness has always believed in the system. However, his faith is tested when he gets to transport a wrongfully convicted teen to state prison. Also, Capone plans to make sure that the kid doesn't make it there alive.
The younger brother of one of Capone's top men is arrested for murder. Will he snitch on Capone's organization or will he stay loyal to the family to the bitter end?
Ness is trying to prove that Capone is blackmailing several important judges. However, he gets sidetracked when he falls for Cleo, one of Capone's callgirls.
Agent Robbins investigates Nitti's attempt to take over a railroad worker's union. Both him and Nitti are working against their bosses' orders on this one.
Capone has his hold over the businesses of a Native Americans tribe, but one of their younger members decides to rebel and hits one of Capone's banks. Ness' team tries to track the kid down first.
The prohibition is ending, so Capone decides it may be time to change his line of work and enter politics. He wants to become a congressman. Nitti, meanwhile, plans to set him up and take him out of the game for good.
Ness must find the one witness who can put Capone behind bars for good. Meanwhile, Capone's men, seeing that the end is near, decide to follow Nitti and drop Capone.