Filmmaker Dick Colthurst went to Mount Everest hoping to learn why people risk their lives trying to reach the world's tallest summit. After spending 48 days in that unforgiving landscape and slogging through hundreds of hours of footage, he has to admit that he failed."While I admire what they do and how they do it, and the sheer mental and physical strength that it takes to do it, I'm honestly no nearer to understanding why they do it," Colthurst, an executive producer for London-based Tigress Productions, said in an interview with The Associated Press.

But Colthurst and his crew did succeed in capturing in vivid and often disturbing detail the hell climbers put themselves through to be able to say they've been to "the roof of the world".

"Everest: Beyond the Limit", which begins its six-week run on November 14 at 11 p.m. Bermuda time on Discovery Channel, chronicles the journey of eight men during the 2006 spring climbing season — the second-deadliest on the Himalayan peak that rises over 29,000 feet.

It's hard to imagine a more motley cast of characters.

There's the asthmatic school teacher from Denmark who is trying to reach the top without supplemental oxygen; the former Hells Angel whose near-fatal motorcycle wreck left him with two metal plates in his head, one in his left knee, tenscrews in his left foot and a steel cage holding his lower back together; a Los Angeles firefighter who sold his Harley Davidson and mortgaged his house to finance a failed summit attempt the year before; a 62-year-old Frenchman who just two months earlier had a cancerous kidney removed through his belly so the incision wouldn't impede his ability to carry a backpack.

The series' "star" is New Zealand mountaineer Mark Inglis. Inglis lost both legs just below the knee to frostbite 24 years ago and is seeking, on specially designed carbon legs with spiked feet, to become the first double amputee to summit Everest.

Leading the expedition is New Zealander Russell Brice, who has put more people on Everest's summit than any other commercial guide and had never suffered a casualty in 13 trips to the mountain.

The series skips the niceties of Katmandu and the picturesque Buddhist monasteries that cling to the valley aside Everest, and takes you straight to base camp — at 17,060 feet already higher than any peak in the Rockies.

At the expedition's start, Brice lays down the law. He says that while the climbers are his paying customers, the Sherpa guides and porters are like his family.

"It's not their job to die alongside you because of your ambitions," he says. "If I see that that's going to happen, I'm going to call the Sherpas away. I will deal with that in court later — and you will die."

Bouncy, topsy-turvy footage shot by cameras mounted on the Sherpas' helmets gives the viewer the queasy, almost stomach-churning illusion of climbing. The camera is unflinching.

You see a climber with brain swelling so severe that his eyes bulge from their sockets. You hear men cough until they retch. You watch as insomnia and oxygen deprivation transform a strapping firefighter into a hollow-eyed ghost stumbling through a place where hunger fades, digestion falters, and the body literally begins to feed upon itself.

Watching Inglis inch upward on his spindly black prosthetics, blood from his raw-rubbed stumps staining the pristine snow, it's hard to know whether to feel inspired by his guts or infuriated at his foolhardiness.

"It's a view to die for," one climber says without a hint of irony in his voice.

Each episode ends in a genuine cliffhanger. Will the rebellious biker heed Brice's order to turn around before his oxygen runs out? Caught in a traffic jam behind a line of incompetent amateurs, will the team physician lose his fingers to frostbite?

There are dramatic rescues. And there is death.

The Tigress crew was there when members of Brice's expedition discovered British climber David Sharp, who froze to death as dozens passed on their way to the summit. The incident made international headlines and brought widespread condemnation down on Brice's head for not mounting a rescue.

A Sherpa's helmet-cam captured Sharp's last words. But Discovery honoured his family's request not to show the footage.

Since the 1920s, Everest has claimed more than 200 lives. During this season, 11 would die.

The series' greatest achievement is how it illustrates the dangerous commercialisation of Everest, capturing both the heroism and hubris of the climbers who go there. For some of Brice's clients the journey brought peace; for others, disappointment and pain.

In the final episode, one climber soaks his blackened, swollen fingers in a futile effort to save them from frostbite.

"I don't regret anything," he tells the camera.

You almost believe him.