Gallo, Violet and Ritter debut their microbrewery business at Winterfest. Brett prepares to present her paramedicine program to an oversight panel. Firehouse 51 gets in the holiday spirit.

Griffin learns the truth about his father’s death and reveals why he really came to visit Casey. Gallo, Ritter and Violet take steps to expand their microbrewery business.

Casey makes a life-altering decision. Gallo, Ritter and Violet agree to an interview and photo shoot. Brett and Mouch launch the paramedicine program. Cruz comes closer to fatherhood.

Gallo clashes with the new lieutenant temporarily filling in for Casey. Severide closes in on a dangerous and deadly arsonist.

The clock is on after Ruzek witnesses a woman’s kidnapping and the team races to put the pieces together. Burgess tries to connect with Ruzek outside of work but he…