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 men and women of Cal Fire and see them in action, using their aerial fleet and ground resources to battle one of the first wildfires of what is shaping up to be a hot and dangerous fire season.

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

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.

The Kilchers finish Atz Sr.'s legacy rebuild and Eivin suffers a loss.

Pandemic parenting pushes Eve to her breaking point as winter approaches.

Atz Sr. reveals his legacy build after months of backbreaking effort.

The Browns complete the main house before a massive wildfire strikes.

A wildfire rages on Palmer Mountain, threatening the Browns livelihoods.

The Browns film their locked-down lives on the mountain before the fire.

E.J. and Jeff are trapped in a pitch-black cavern surrounded by bears.

E.J. and Jeff are surrounded by lions on South Africa’s Wild Coast.

E.J. and Jeff face elephants and hippos in Botswana's Okavango Delta.