Lesson 38: Biba-Biba! Another Retsu

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.

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.

In a ruined and toxic future, thousands live in a giant silo deep underground. After its sheriff breaks a cardinal rule and residents die mysteriously, engineer Juliette starts to uncover shocking secrets and the truth about the silo.

Between 1896 and 1899, more than 100,000 brave souls set out on a perilous journey into the frozen North on the legendary Klondike Gold Rush trail. Most never made it to the end. Killed or scared off by bears, treacherous terrain, raging torrents and temperatures below -40 degrees, only one in three completed the journey. Now Parker Schnabel of Discovery GOLD RUSH fame, will attempt to make this same journey and document it in Gold Rush: Parker's Trail.