| Episode cast overview, first billed only: | |||
| Jason Beghe | ... | Hank Voight | |
| Jon Seda | ... | Antonio Dawson | |
| Sophia Bush | ... | Erin Lindsay | |
| Jesse Lee Soffer | ... | Jay Halstead | |
| Patrick John Flueger | ... | Adam Ruzek | |
| Marina Squerciati | ... | Kim Burgess | |
| LaRoyce Hawkins | ... | Kevin Atwater | |
| Archie Kao | ... | Sheldon Jin | |
| Elias Koteas | ... | Alvin Olinsky | |
| Melissa Sagemiller | ... | Detective Julia Willhite | |
| America Olivo | ... | Laura Dawson | |
| Isaac White | ... | D'Anthony | |
| Arturo Del Puerto | ... | Adres Diaz aka Pulpo | |
| Monica Raymund | ... | Gabriela Dawson | |
| Lauren German | ... | Leslie Shay | |
In the series premiere, after a slew of brutal slayings, District 21 led by Sergeant Hank Voight go after a Colombian drug cartel cleaning house in Chicago. They discover D'Anthony 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 Adam Ruzek is pulled from the police academy by Olinsky to join the team. Written by Anonymous
It's so refreshing to see and different kind of cop drama it has ever and just when you thing it can give anymore it does amazing!!