Narrator

After Neurosurgeon Maggie Sullivan's personal and professional life are thrown into turmoil she returns home to Sullivan's Crossing. While there, Maggie is forced to navigate her complicated present while confronting the painful past she has chosen to ignore for years.

District 21 of the Chicago Police Department is made up of two distinctly different groups. There are the uniformed cops who patrol the beat and go head to head with the city's street crimes. And there's the Intelligence Unit, the team that combats the city's major offenses - organized crime, drug trafficking, high profile murders and beyond. These are their stories.

No job is more stressful, dangerous or exhilarating than those of the Firefighters, Rescue Squad and Paramedics of Chicago Firehouse 51. These are the courageous men and women who forge headfirst into danger when everyone else is running the other way and whose actions make the difference between life and death. These are their stories.