Tyrone Brown

A familiar face steps in when an intelligence detective is abducted by a heroin kingpin. In the season premiere, Intelligence is in pursuit of Derek Keyes (guest star Bokeem Woodbine), number one on Chicago's Most Wanted list and heroin kingpin. Meanwhile, Halstead (Jesse Lee Soffer) tries to get through to Lindsay (Sophia Bush) as her downward spiral continues after her three-week absence from the unit. At District, Olinsky (Elias Koteas) opens up to Platt (Amy Morton) about a secret from his past. Roman (Brian Geraghty) expresses his concerns to Burgess (Marina Squerciati) about what she's getting into by marrying Ruzek (Patrick John Flueger).

The DA's office asks Bull to assist them in their prosecution of a fraternity when a pledge accidentally drowns during a hazing incident, but his efforts may be derailed when the students close ranks to stonewall him.