While out on a bank run for his off duty security job at the dispensary, Halstead (Jesse Lee Soffer) and his co workers find themselves under attack by a violent robbery crew which quickly becomes a full scale shootout. Voight (Jason Beghe) and Lindsay (Sophia Bush) question the owner of the dispensary who mentions her business has received threats from local gangs upset she's cutting into their revenue. Meanwhile Roman (Brian Geraghty), Burgess (Marina Squerciati), Antonio (Jon Seda), Halstead, Ruzek (Patrick Flueger) and Atwater (LaRoyce Hawkins) follow up on a lead and track down a potential suspect.