The investigation leads Intelligence to one of Chicago's wealthiest families after a nighttime photographer is murdered over a piece of mysterious footage; Burgess' sister Nicole visits the district and presents an icy attitude toward Ruzek.
When Burgess realizes that her sister, Nicole, never made it home after a night out with friends, the members of the intelligence team make finding Nicole their top priority.
The team hunts for a young man who is using napalm-style bombs to attack his targets; with Tali away, Jess and Sarah begin to adjust to their empty nest.
Two brothers plot revenge against the company that caused their town's environmental destruction.
The team must protect Ortiz's former informant after a hit man tries to kill her.
