Mia Park

Lt Casey must work with Voight and the Intelligence Unit, Shay grows increasingly excited about the prospect of motherhood, and everyone comes together to support the opening of Molly's.

The Firehouse 51 crew have their work cut out for them when a tornado hits the city. Also, Brett must report Chilli after she makes a big mistake.

The team find a surprising connection between two elderly patients presenting similar symptoms. Dr Manning loses her wedding ring.

Dr Manning investigates a young boy's background after the child is admitted with a broken wrist. Dr Choi tries to deal with an erratic patient.

Charles and Manning disagree on how to handle a patient who is poisoning herself, while Halstead has suspicions about Natalie's new boyfriend.

As the city is thrown into chaos by freezing temperatures, Sylvie gets trapped in a life or death situation. Plus, an abandoned baby is found at the Firehouse.