An epic adventure begins when a massive sinkhole opens in the middle of Los Angeles, pulling hundreds of people and buildings into its depths. Those who fell in find themselves in a mysterious and dangerous primeval land, where they have no choice but to band together to survive. Meanwhile, the rest of the world desperately seeks to understand what happened. In the search for answers, one family torn apart by this disaster will have to unlock the secrets of this inexplicable event to find a way back to each other.

Kelly Clarkson presents the biggest newsmakers and names in film, television and music; as well as emerging new talent and everyday people who are beacons of hope in their communities.

An edge-of-your-seat view into the lives of everyday heroes committed to one of America's noblest professions. For the firefighters, rescue squad and paramedics of Chicago Firehouse 51, no occupation is more stressful or dangerous, yet so rewarding and exhilarating. These courageous men and women are among the elite who forge headfirst into danger when everyone else is running the other way and whose actions make the difference between life and death.