Lisseth Chavez

After zeroing in on a suspect responsible for bioterrorism, the PD prepare to undertake their biggest manhunt yet; Upton is torn between helping track down the perp and providing emotional support to a scared young girl who needs her.

After a botched carjacking turns out to be something much bigger, Voight's unit goes toe-to-toe with a smart drug kingpin who only works with women; new recruit Vanessa Rojas struggles with the transition from undercover to Intelligence.

A murder in a Bulgarian neighbourhood results in a challenging investigation when locals won't talk to police; Ruzek has a clash with a patrol officer.

The shocking murder of young boys affects Halstead; Crawford encourages Intelligence to use new facial recognition software to help identify a suspect, but the plan backfires.

Dr Manning's actions with a recent patient lead to serious repercussions; April and Noah disagree over a patient who is injured after a beating; Dr Charles is visited by a childhood friend with a surprising revelation.

Voight pulls Darius in after Crawford asks intelligence to investigate a dangerous drug, but there is little trust in the relationship. When their plan to nail a dealer goes awry, the team must make a tough decision about Darius.