Melissa Carlson

In responding to a call Atwater (LaRoyce Hawkins) and Burgess (Marina Squerciati) discover a gunshot victim and the only witness is Lexi Olinsky (guest star Alina Taber). The shooting is tied to a Latin gang. To protect Olinsky's (Elias Koteas) daughter, Voight (Jason Beghe) takes the case from the Gang Unit. Ruzek (Patrick Flueger) pulls up Burgess to help with an undercover mission that he hopes will help solve the case.

As Antonio’s (Jon Seda) life is now in question, Voight (Jason Beghe) and Platt (guest star Amy Morton) open up about their pasts. Jin (Archie Kao) is caught while tinkering with Voight’s computer and uses the only scapegoat possible to keep him in the clear. At the same time with Charlie (guest star Billy Wirth) back in town Lindsay (Sophia Bush) realizes she’s going to have to come clean about a few things. Halstead (Jesse Lee Soffer) finally gets answers he’s been wanting about Voight’s and Olinsky’s (Elias Koteas) past.

While Platt (Amy Morton) tries to manage a chaotic desk area, a man struggling to get her attention takes a drastic action and demands that the unit find his missing daughter. At the same time, Commander Fischer (guest star Kevin J. O'Connor) informs Voight (Jason Beghe) that Bunny (guest star Markie Post) is bringing up new accusations on a case from his past. Lindsay (Sophia Bush) urges her mother to fix the situation. Meanwhile, Antonio (Jon Seda) is shocked to learn a secret Olinksy (Elias Koteas) has been keeping.

Intelligence sets out to find a missing teenaged boy who they believe poses a serious threat to the students at his wealthy school after finding disturbing drawings in his notebook. Meanwhile, Atwater (LaRoyce Hawkins) is eager to make a good impression on a prominent African American police Captain (guest star Eamonn Walker) and Olinsky (Elias Koteas) and Michelle (guest star Madison McLaughlin) find themselves in a difficult situation and turn to Ruzek (Patrick Flueger) and Burgess (Marina Squerciati) for help.

When the father of one of the dead girls explains that he paid Dennis Lee (guest star Kelvin Han Yee) to have her brought to America, this hits home with Olinsky (Elias Koteas). Lee is one of the Chicago's most wanted fugitives and escaped Olinsky once before. Intelligence isn't about to let Lee dupe them again and Olinsky's past files prove valuable in finding Lee's whereabouts. Meanwhile, Sean Roman (Brian Geraghty) has an altercation with a fellow officer which lands him in a bit of trouble. At the same time Platt (Amy Morton) helps prepare Nadia (guest star Stella Maeve) to take her polygraph test after passing the CPD written exam.