Tracy Spiridakos

Intelligence investigate a bank robbery which leads them to a teenage gang run by an older criminal. Another detective from the robbery-homicide division tries to take over the investigation.

After a video is posted online showing the beating and murder of a man burnt alive, Intelligence tracks down a group of vigilantes torturing and killing sex offenders.

Lindsay deals with the consequences of her actions when her mother is suspected of murder. Meanwhile, Lugo gives Voight an ultimatum.

Chief Boden unwillingly agrees to let Dawson and Brett go under cover; Kidd and Zach's relationship hits a bump; Cruz has a hard time expressing his true feelings for Brett.

An entire apartment complex is forced into quarantine when cases of the deadly virus turns into an epidemic.

A rare but deadly bacteria takes its toll on numerous victims around the city, leaving Chicago's finest first responders to work together alongside the CDC to resolve the dangerous situation. Severide suspects something bigger is happening.