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.

When Erin and Jay are called to a shooting at a family home, it appears the father's dark dealings with a dodgy pyramid scheme may be responsible for his loved ones' deaths.

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

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.

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.

The shooting of Dr Charles moves to the courtroom. Dr Halsted and Dr Manning work on a heart-wrenching case.