Brandon Harkness fights his way up a mountainside in the 29-tonne Tigercat. Wade Ettiene's 'Big Mama' takes a two-inch steel sawtooth to her face, and Buckin' Billy's son Hogan loses his grip while cutting a tree 60-feet off the ground.

Experts question what probes on Mars may have found over the past 40 years. Could NASA be hiding proof of life on the Red Planet from the public?

The Big Dogs are back, along with incredible craftsmanship and massive tyres, featuring a 1951 Chevy pickup and 1971 GMC pickup. The Silo Pulldown and Four Horsemen show no mercy in vanquishing trucks, and it's a run for the ages in the Green Hell.

Four bladesmiths return to the Middle Ages when they are tasked with forging a Crusader's Dagger from a thick rod of W1 steel.

Rygaard blows out the cobwebs as the company begins logging on their massive, new job. Wade Etienne battles rising mud, trying to get his logs off the jobsite and Buckin' Billy's forced to take down multiple trees at the same time.

Throughout history, spiritual leaders known as Shamans have healed, protected and advised. Could they really be in contact with extraterrestrial realms?

Five drivers put their personal trucks to the test. The first challenge hurts more than a driver's pride when one truck is broken in half.

Four bladesmiths must start from the ground up, building their own coal forges using materials scavenged from a storage unit.

Danny Pihl pushes himself physically and mentally while running his first jobsite on his own. Frank Harkness' fast work ethic proves too much for his equipment while on a steep, snow- covered mountainside.

Could insects have descended from extraterrestrials? Experts investigate whether Earth's 10 quintillion critters could have dangerous links to aliens.

Truck Night goes back to the '90s, featuring a line-up of rigs from the millennium's last decade. An emotional story motivates one driver, and a razor thin margin separates the two finalists when they face off in the Green Hell.

Four bladesmiths are challenged with forging a canister damascus knife using only steel wool and 1095 powder. If that wasn't difficult enough, they must also forge a gut hook into their blades. Getting this wool welded is wicked work, and the smiths struggle to forge this porous steel. After two gruelling rounds of competition, two smiths are dealt a kick to the gut and eliminated, while the final two head home to recreate an important weapon from North American history: the Pipe Tomahawk. One smith's dreams will go up in smoke while the other will claim victory, earning $10,000 and the title of Forged in Fire Champion.

Explore how the biggest vehicles on earth - planes, trains and ships - are repaired and transformed within an incredibly short space of time.

Some of the most innovative and mindboggling cars are not on the streets, they are helping the military pound the pavement and cross terrain around the world. From an amphibious truck that can charge over deep sea and water in a flash to a six-wheeled Humvee with more firepower than some tanks, Chuck Norris takes viewers on a tour through the wildest vehicles in the history of the Armed Forces.

More truck owners from across the USA compete in gruelling challenges that test their ingenuity and driving ability.

The strongmen are in the United Kingdom, home of Eddie Hall and Britain's original strongman, Thomas Topham. Nick refuses to back down as he and Brian go head to head in a dangerous barrel-lifting competition.

Ivy gets excited by the prospect of high-end lockers. Rene and Casey struggle to agree and Darrell tries to distract his rivals with some old-fashioned pranks.

The pressure falls on Darrell and Brandon to drum up merchandise for their website. Plus, Jarrod and Brandi put a bidding strategy to the test. Will it work?

It's spring break so Jarrod and Brandi bring their kids to the auction. Meanwhile, Darrel puts his 'Gambler' nickname to the test.

Jarrod and Brandi have some fun as they attempt to beat the competition. Meanwhile, Casey tries her hand at bidding.

A breakdown forces Jason to choose between the job and his crew's safety. Frank gets caught in a whiteout and Buckin' Billy sets his son the ultimate test.

Theorists ask whether a currently unidentified species represented in our DNA could be a result of breeding between humans and aliens in the remote past.

Broken trucks litter the course when the water and mud of the White Out shuts down one truck and the Silo Pulldown breaks another. The Green Hell has a surprise finish leading to an emotional result.

Four bladesmiths must forge judge Ben Abbott's favourite blade, the Celtic Ring Knife, using the San Mai technique. This proves to be no easy feat as the smiths battle derailing delaminations and cracks. After a gruelling round of testing, the final two competitors return to their home forges to recreate a lethal weapon from history: the Irish Ring Hilted Sword. Whose blade will skirt disaster to earn the title of Forged in Fire Champion and a check for $10,000?

Craig finds out his son has made a disastrous and costly error. Buckin' Billy makes an exciting discovery when he takes cover from a storm.

Experts question whether ancient myths provide evidence that reptillian aliens are more than just pop-culture creations and staples of science-fiction.

An awesome variety of trucks pull up to the start line on Whiteout. The impossible happens in the Slingshot and tension mounts when the fire department is called in. The Green Hell strikes again, taking out a truck in an ending no one saw coming.

Four bladesmiths honour some of the greatest Americans of all time - the Presidents. First, competitors pay homage to famed adventurer, President Theodore Roosevelt, by forging a replica of his Rough Rider Bowie.