Episode 4

Across continents and decades, five brilliant friends make earth-shattering discoveries as the laws of science unravel and an existential threat emerges.

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.

On Last Week Tonight with John Oliver, John Oliver presents a satirical look at the week in news, politics and current events.

An emotional thrill ride through the day-to-day chaos of the city's newest state-of-the-art trauma center and into the lives of the courageous doctors, nurses and staff who hold it all together. This is one of those days.

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.