The Magnificent City Of Chicago. The big wedding day arrives and Firehouse 51 welcomes Casey back to celebrate the joyous occasion. Emma's plans to replace Violet come to a shocking end.
Firehouse 51 must band together when one of their own is taken hostage.
Following an injury in an industrial fire, Severide investigates an anonymous tip. Kidd searches for someone to fill the open spot on Truck 81. A possible new recruit gets tested at a call.
Cruz forms a bond with an immigrant boy he meets while fighting an apartment fire. Squad plans to prank the newest member of their team. Hawkins and Violet struggle to keep their relationship a secret.
Last Chance. Lying Doesn't Protect You From The Truth. Dylan and Ethan treat a patient shot during a drug raid. Charles and Vanessa work together to properly diagnose a motivational speaker.