In a small warehouse here, two men stand behind a Plexiglas shield, waiting for a disposable lighter to burst into flames. A golf club attached to a pneumatic arm swings down at 85 miles per hour and slams into a piece of wood where the lighter is perched. With a loud snap, the wood and lighter fly across the room and hit a wall.

"The whole thing jumped - did it hit the lighter at all?" asks the redhead.

MYSTERY SLEUTHS: Adam Savage (in the spacesuit, left) and Jamie Hyneman host Discovery Channel's 'Mythbusters.' ANN SUMMA/DISCOVERY CHANNEL

The other man bends down and discovers a crack at the base of the arm, anchored by sandbags. "I guess it needs more weight," he says.

The two men are not pyrotechnic experts, nor are they pyromaniacs. They are Adam Savage and Jamie Hyneman, the game and affable hosts of the cable television hit "Mythbusters."

Since its premièr in October 2003 on the Discovery Channel, "Mythbusters" has taken on urban legends and modern-day tall tales that keep us up at night: Does a rolling stone gather moss? Can a penny dropped from the Empire State Building kill a person? Will water stop a bullet? Today, they are testing a yarn that has swirled around caddyshacks for years: that a butane lighter will explode when teed up and struck by anyone other than Tiger Woods.

Each week, Messrs. Hyneman and Savage conduct experiments to determine whether a given myth can be busted, confirmed, or deemed plausible. Viewers around the world now sleep soundly, knowing a rolling stone does gather moss but can't grow it, air resistance prevents a penny thrown from the Empire State Building from becoming a deadly weapon, and, yes, water will stop a bullet. In the process, the duo may have cleared up one other phantasm: how two men - one a teenage runaway, the other a gregarious former magician and unicyclist - got their own TV show and became minicelebrities.

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Hosting a TV show was the last thing on Hyneman's mind when he got a call to audition from executive producer Peter Rees. Mr. Rees had remembered meeting Hyneman on another TV series, "Robot Wars." Hyneman asked if he could bring along Savage. Three weeks after sending in a demo tape, they began filming in San Francisco.

"The host criteria was the total opposite of the normal television host," Rees says. "We wanted someone who had a shop ... someone who could build anything we wanted, but we didn't want a scientist."

It was a match. What Hyneman and Savage lack in formal scientific discipline they make up for in determination, wit, and instinct. Best of all, they possess a combined 30-year career in special effects. Their work can be seen in dozens of movies ranging from "Anaconda" to "Gremlins" to the "Star Wars" and "Matrix" trilogies.

Like special effects, myth busting is all about "contingency planning," Savage says, which suits him just fine. As a kid, he taught himself to perform magic, juggle, and ride a unicycle, among other talents. He began building toys at age 5. His father was a painter and occasionally created animated segments for "Sesame Street," so the arts played a big role in the Savage household.

"Anything I wanted to try, I could try," says the carrot-topped Savage.

And try he did. He worked stints as an animator, graphic designer, set designer, and actor before settling into special effects.

Hyneman grew up on an apple orchard in Columbus, Ind. "We didn't have any neighbors for miles, so we were left to our own resources," he says. Being resourceful came in handy when Hyneman was about 14. He ran away from home for six months after his parents threatened to send him to reform school because of "unruly behavior." The adventure ended in California, where Hyneman spent a few days in juvenile detention until his parents brought him home. He later owned a pet store and operated a boat-charter business in the Caribbean.

Eventually, Hyneman decided to try special effects because it seemed a lot like sculpting - one of his passions - but less static. Today he owns M5 Industries, a special-effects shop, where he and Savage build their experiments. Hyneman has a degree in Russian literature and looks like a character in a Tolstoy novel, with his walrus mustache, rimless glasses, and black beret.

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Since its inception, Mythbusters has slowly built a cultlike fan base that includes everyone from 8-year-olds to bomb experts to grandmothers. Starting its fifth season in January, the show is now broadcast on four continents. To producers, the show's popularity stems in part from its participatory ethos. Roughly 30 percent of the myths tested come from viewer suggestions. "The show is really about involving people in the process," says Rees.

Yet viewers are clearly attracted by the engineering feats and curiosity about the myths. Lisa LaVigne, a computer technician in Detroit, was channel-surfing one day in 2004. She stumbled on a "Mythbusters" marathon and watched for nine hours. "It made me use my brain," she says. "It made me want to look stuff up, which is rare nowadays for TV."

The antics of the two hosts also give the show a certain frivolity. "It's the kind of things 13-year-old boys would do," says Jay Mechling, a history professor at the University of California, Davis.

Despite their budding fame, Hyneman and Savage live somewhat anonymously in San Francisco. The two admit that being recognized is fun, but it did take time to adjust. "I've had people go 'hey!' and I turn around and they just stare," Savage says. "They have nothing else to say."

It took Hyneman a of couple years to feel comfortable talking in front of a camera, let alone to strangers on the street. "You have to remember that I'm a guy who is happiest in a dark room just thinking," he says. "I'm not a sociable person. I don't like to talk."

Savage, on the other hand, is outgoing. They're clearly the Oscar and Felix of myth busting. "The two are diametrically opposed in every aspect of their lives," says Rees. "Jamie is all about total, complete, and utter control. Thinking first and then acting. Adam is about acting first and then thinking."

Without prodding, the two own up to their differences right away. While definitely not dinner companions after hours, the two respect each other on the job. "I wouldn't spend five minutes with Adam outside work if I didn't have to," says Hyneman. "But yet I feel somewhat displaced without him in the workplace ... destroying my tools and leaving messes everywhere he goes."

The task today is to get the disposable lighter to burst into flames. They try again. Nothing. A high-speed playback machine shows the lighter shattering and the butane spilling out. Undeterred, the duo devises a new plan. "If we actually knew what we were doing, it wouldn't be any fun to watch," Hyneman says later. "But we usually get on top of things quickly enough."

Both men say the biggest perk about doing the show is what they learn along the way. Hyneman calls it "incredible."