Kidd and Severide’s honeymoon is interrupted by a dangerous person from their past. Kidd’s former academy classmate joins Firehouse 51. Brett and Violet reflect on their relationships.

Mouch and Ritter work together to solve a murder mystery. Severide and Cruz tackle a food truck fire. Gallo goes to see Hawkins about Violet.

When the shooting of a young girl happens in their neighborhood, Cruz and his brother, Leon are forced to think about the gang they have tried to escape. The battle…

All seems lost with firehouse 51 on the verge of closing its’ doors, thanks in no small part to Gail McLeod, but Chief Boden and the rest of the house…

Loy plays with fire, Josto wears his heart on his sleeve, Oraetta makes a surprising discovery and Deafy closes in on Zelmare and Swanee.

Loy forms an uneasy alliance, Odis finds peace, Josto settles the score, Ethelrida takes a risk and Oraetta gets spooked.

Josto gets revenge, Oraetta comes clean and Ebal teaches Loy a lesson about business.

The Smutnys receive unexpected guests, Josto and Gaetano reunite, Loy challenges the status quo and Oraetta is caught.