Stepping Stone. When District 21 goes after a Colombian drug gang following a series of brutal slayings, an asset in the investigation emerges.

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.

Chin Check. Voight and the team check out a house that has been associated with a series of gangs, people from the past cause Halstead's temper to rise.

Now Is Always Temporary. Olinsky tries to protect his daughter, a counterfeiting operation is investigated, when a hoarder is arrested, more than clutter is uncovered.

Thirty Balloons. Atwater and Burgess must keep their new patrol car in mint condition, the Intelligence Unit uncovers drug smuggling, Voight's behavior toward Lindsay drives her right where he doesn't want her, tensions rise between Olinsky and Ruzek.

Conventions. New York's SVU agents Fin and Rollins help track down a serial killer who rapes his victims, Burgess gets an opportunity to prove herself, Lindsay brings Halstead as her date to her high school reunion.