Stepping Stone. When District 21 goes after a Colombian drug gang following a series of brutal slayings, an asset in the investigation emerges.
When the CBI investigates the murder of an antiques dealer found dead in a museum, the evidence indicates that the suspect may be a member of the team.
Wrong Side of the Bars. Antonio believes a Colombian gang is involved in his son's kidnapping, Halstead learns new information about Lindsay, Voight offers Antonio a new way to get information about Diego's whereabouts.
A look at the lives of employees at a big box store.
The Docks. Platt and Voight discuss their pasts, Jin uses a scapegoat when he is caught tinkering with Voight's computer, Lindsay realizes she needs to come clean.