S1, E1: In the series premiere, after a slew of brutal slayings, District 21, led by Sergeant Hank Voight (Jason Beghe) go after a Columbian drug cartel cleaning house in Chicago. They discover D'Anthony (guest star Isaac White) who proves to be an asset in the investigation. At District, complicated histories and unit rivalries surface which could end up costing them one of their own. Meanwhile, Rookie Kyle Ruzek (Patrick Flueger) is pulled from the police academy by Olinski (Elias Koteas) to join the team.