The Untouchables S03E09 - City Without a Name

After a Federal Agent is gunned down, Eliot Ness and his Untouchables arrive in town to try and solve their colleague's murder. The perpetrator is believed to be Lou Mungo and his precipitous action is exactly the opening Frank Nitti was waiting for so he could move in himself. Nitti hires the smooth talking gambler Sebastian to convince Mungo to hand over his contacts at City Hall and he soon has the information he needs to blackmail Mungo.