Contestants compete for a shot at $25,000 as they brave a battleground.

A tattooed trainer flexes her muscles against a martial arts master. A benchwarmer in search of a comeback takes aim at a sporty single mom. With $25,000 on the line, only the strong survive the Thunderdome.

Meet the brave members of Cal Fire, and see them in action.

Firefighters pick which house they can save, and which they must let burn.

A California resident refuses to leave his home amid raging wildfires.

As the Creek Fire explodes into the largest wildfire in California history, residents of Fresno County scramble to evacuate. But over 400 campers are trapped by a wall of flames, sending Cal Fire and National Guard pilots on a daring rescue mission.

Cal Fire fights to save a family-owned winery from the Glass Fire.

Firefighters battle a new wildfire on a somber anniversary.

Dredgers brave the frigid Alaskan waters hoping to strike gold.

A rainy day leads to trouble when Shawn gets hurt in a bar fight.

Sunny weather brings all dredges out to sea, but conflicts quickly arise.

Sky-high summer temperatures cause miners to search for new strategies.

The Myrtle Irene gets stuck in the mud and Elaine makes up for lost time.

Ken tries a new perspective to find new ground.

Shawn fights the shifting tide, and new diver Ben saves Vernon's day.

Tensions fly as Brad leads The Reaper into hostile waters.