The aftermath of several major events and delves into the complex relationships within the Intelligence Unit. The investigation into a series of bombings targeting the media, the murder of a prominent alderman, and the fallout from Woods' relentless pursuit of Voight. They explore themes of corruption, undercover work, and the personal toll of police work, culminating in a devastating loss for the team and with Halstead being shocked when he finds out that Erin Lindsay had left Chicago without notice and on top of that receiving new partner Hailey Upton.

Meanwhile, the Intelligence unit investigates an escalating gang war that involves an accidental death of a young child. Voight seeks the help from Antonio Dawson which later asks him to return to Intelligence full time. Also, Burgess returns from her leave.