This show follows the turbulent lives of firefighters and paramedics in the Chicago Fire Department. After the death of fellow fireman Andrew Darden, officers-in-charge Lt. Matthew Casey (Jesse Spencer) and Lt. Kelly Severide (Taylor Kinney) break and gain loyalties as they blame each other for Darden's death. Feeling even more guilt after learning that Darden's wife also blames him for the death of her husband, Severide has to put aside his differences and emotions to come together with his firehouse family after the near death of another co-worker Chirstopher Herrmann. Joining in the chaos is firefighter candidate Peter Mills, following in his late father's footsteps with objections from his mother, and paramedics Gabriela Dawson and Leslie Shay. Together they help protect the city of Chicago while looking out for each other.