Severide steps in as ranking officer at 51. Kidd fights to save her Girls on Fire program. Cruz's family is threatened when someone from Javi's past resurfaces.

Severide gets wrapped up in an Illinois State Police investigation after discovering illegal guns on a call. A bird harasses Mouch on the apparatus floor. Kidd keeps an eye on Carver.

After a daring rescue at an adventure park, Kidd asks Severide to create a ropes course for Girls on Fire. Violet’s former nemesis returns, pleading for her help.

With the crew stretched thin, a performance efficiency expert evaluates Firehouse 51. Kidd and Severide bond with the mother of the baby they hope to adopt.