Voight and Antonio enlist the help of agents at the Special Victims Unit in New York, Fin and Rollins, to help track down the culprit of a series of rape/murders. Burgess has an opportunity to prove herself to Intelligence. Elsewhere Lindsay enlists the help of Halstead to act as her date for her high school reunion to get back at an old rival.

Voight is assigned a new Internal Affairs handler, Stillwell who proves to be suspicious of Voight's actions. During an investigation involving a gambling ring Voight is forced to work with his former partner from the Gang Unit, Shi. At the same time Halsted remains fixated on Lonnie Rodiger and enlists Jin's help to gather more information. Meanwhile, Ruzek's inflated ego leads Olinsky to take him down a peg and offer a great opportunity to Atwater.