Thanksgiving proves to be a busy holiday for the firehouse - including a visit to a meth lab, a gang shooting and a 10-car pileup.
Jose Vargas is forced to go on disability after sustaining an injury in a fire; Severide receives a tempting invitation from a woman he saved from a car crash; Cruz tries to end his brother's involvement with a gang.
An expensive necklace goes missing at the scene of a fire, leading to an internal investigation; Cruz makes a desperate decision to save his brother from a gang war; Dawson invites Casey to a party.
Tension builds when a group of rabble-rousers attempts to lock down the firehouse; Brett is faced with a monumental decision; Cruz readies himself for a big day; Gallo and Ritter attempt to launch Firehouse 51 into the social media age.
Cruz struggles with guilt and decides to make a confession to Casey; Severide asks Dawson for help with his injury; Herrmann is faced with an unpleasant business deal.