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.
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.
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' team hits Capone's operations hard. One of the raids ends in a shootout and two civilians are killed in crossfire. This leaves Eliot worried that things might escalate out of control if the raids continue to be violent.
Lingle, the sleazy journalist Ness used to feed Capone with false information about Ness' operations, is found dead. Ness is adamant to find the perpetrators. What he uncovers is a web of corruption.
In an effort to catch the child-killer as soon as possible, Ness agrees to a temporary alliance with Capone. However, Capone has no intentions of giving the killer up to the police. If he catches him first, he will kill him.
Childhoods of Al Capone, the future ambitious gangster who'll try to become the crime boss of the prohibition era Chicago, and Eliot Ness, the future head of "The Untouchables", a team of incorruptible agents formed to stop Capone.
The head of a local worker's union that's on strike is approached by Capone, who offers him help in the battle for his union members' rights. Ness warns the man that offers from scheming Capone always come at a heavy price.