The prophet speeds through Silicon Valley in a red Corvette convertible, up Highway 17 to Highway 85 to Highway 101. Joe Firmage is racing to the offices of USWeb/CKS. He started the company three years ago in a moment of inspiration, and it now has a market value of $2.5 billion. Joe Firmage, at the age of 28, is a winner.

Another red Corvette whizzes by. Another young businessman, going faster. This is a Darwinian world -- speed is of the essence.

Firmage soon arrives at his office building, which is like every high-tech office for miles around, so new it's barely had time to experience the phenomenon of rain. Firmage rides an elevator, goes through double doors and strides down a clean, carpeted hallway past secretaries and staffers, everyone tapping on keyboards and talking on the phone. They're all engaged in an extremely profitable pursuit that didn't even exist a few years ago. USWeb/CKS provides "Internet services." The people here set up "e-commerce" sites and "intranets" and "extranets" for other companies. Firmage says proudly, "We are probably the single largest concentration of Internet experts in the world."

He used to be the ultimate boss here, the CEO. Now he's just a consultant, the resident prophet in the corner office.

He devotes himself to his mission. His mission is "The Truth."

That's the title of his book, which is posted on the Internet at www.thewordistruth.org. Joe Firmage believes he has found The Truth, and he is using all his entrepreneurial skill to disseminate that truth to the world at large.

In a single month, his Web site received 6 million hits. He's placed a full-page ad in USA Today. He is about to be profiled in Wired and Rolling Stone. The local papers have followed his recent moves. He's a hot topic in certain Internet chat rooms -- a sudden silicon celebrity.

The Truth according to Firmage is that the world is about to change dramatically. Of course that's what every visionary says. In these millennial times, there are futurists and big talkers crawling all over California and the rest of the planet. Firmage knows he has to speak louder than others to be heard over the background static. Thus his assertion that human beings are about to master the force of gravity.

We will learn to engineer the very fabric of "space-time." We'll tap into a massive, hidden energy source. Aspects of nature that everyone has always taken for granted -- like this annoying thing called "inertia" -- will enter the realm of human manipulation. We'll zip around the planet in a flash. We'll zoom across the entire galaxy -- really fast!

"You could go to Alpha Centauri and be back for dinner," Firmage says.

And there's more! The gravity breakthrough is merely a harbinger of the really huge development, the paradigm-shattering event to end all paradigm-shattering events. We will make contact with . . . the Visitors. We're talking formal contact here, actual direct communication, no more cat-and-mouse games in the desert. No more coverup. We will know the aliens and discover, finally, our place in the cosmos.

That's "The Truth."

Whether he's right or wrong -- brilliant or boneheaded -- Firmage is clearly a creature of his time and place. The temptation is to prop him up as a Generation X figurehead, and the press has been unable to resist the urge to call him the Fox Mulder of Silicon Valley. A better way to look at the situation is to say that he's the Internet in human form.

He's the human search engine. He is a nexus for provocative and questionable information. From his corner office, he can tap on the computer and dart through an unofficial and unauthorized world of knowledge and rumor. He can amass, as he swivels in his chair, his own personal database of facts and theories. To listen to Firmage is to hear of the Casimir effect and zero-point energy and Heisenberg's uncertainty principle and quantum foam and the Roswell incident and the MJ-12 documents. Science, pseudo-science, truth and fiction, God and electromagnetism: It's all there, a thick and pungent stew.

He would like the world to think that someone has come along, someone intelligent and bold and most of all spiritual, who can make sense of it all. He would be the man who reconciled science and religion, who legitimized the UFO mythology and who figured out the future, even though it meant abandoning his wildly lucrative career as an Internet guru. As he told a local paper, "I chose to basically take the risk for everybody's sake and put my own career on the line."

But another story line is in play -- that what works in Silicon Valley does not always work in the real world. That here's a case of someone who couldn't separate the good information from the bad. That with enough hubris, even Joe Firmage, so young and smart and clever and rich, might find a way to make a fool of himself.

THE PATH

Firmage is polite and personable, but when he gets rolling, his fervor builds. He puts the tractor beam on his listener and doesn't let go. There are moments when his eyes appear sad, and weary, as though affected by the tedium of explaining things that should be obvious.

He says things like:

"The macro picture here is anthropological in dimension."

Firmage resides in a million-dollar house in Los Gatos that shows little evidence of a human occupant. There's a pool table just off the kitchen (he is quite good at billiards, he says) and a laptop on the counter with, by Firmage's estimate, 2,000 unanswered e-mail messages. He says he typically works 15 hours a day and does not have the "bandwidth" at the moment to get married or have a permanent relationship.

Firmage is the descendant, through many generations, of another bold searcher, Brigham Young. Young led the Mormons to Utah after the murder of the prophet Joseph Smith. Firmage grew up in a Mormon household in Salt Lake City.

When he was 10 years old, his father, a law professor, insisted that he watch Carl Sagan's PBS series "Cosmos." Young Joe found it transformational. He became fascinated by astronomy. In his back yard, he took pictures of the heavens with a camera attached to a telescope.

In his bedroom, he tinkered with computers. One day he tried to write a software program on a Macintosh, and found the job laborious. He had to dive down into the deepest structure of the Mac's brain. This is too hard, he told himself. Suddenly he had an idea. He'd make this simpler for everyone. He designed a set of software tools that could be used by anyone to write a program. He formed a company, Serius Corp., based in his bedroom. He stayed up late at night, shrink-wrapping boxes of Serius software.

His invention was a hit. Although he went on to the University of Utah, studying physics, he didn't stay long. Firmage had found his calling: computer world entrepreneur.

People with money were looking for computer whizzes. Investors gave him millions of dollars, the business expanded, and soon Firmage had 45 employees in a fancy office. Novell Corp. came along in 1993, waving $24 million. The huge company bought Serius and made Firmage a vice president. He was 23 years old and a millionaire.

Two years later, in the fall of 1995, he quit Novell, and with a colleague, Toby Corey, he started USWeb. Firmage's new, big idea was that corporations all over the world were befuddled by the Internet and needed smart people to guide them through the wilds of this new medium. USWeb wouldn't make products, it would provide services. The company bought out more than three dozen other firms. Firmage was a winner yet again.

He's not shy of touting his intellectual skills and professional successes.

"I could have done anything in this industry."

"We did something far more challenging than Yahoo or Amazon.com."

"People describe me as incredibly rational, very left-brained, highly attuned to risk management, all the qualities that make a good CEO."

The rule in Silicon Valley is adapt or die. To be slow, to cling to tradition, to fail to envision the next big thing, is to ensure extinction. By the fall of 1997, Firmage and his partners were ready to take USWeb public, a move that required a frenzy of activity in preparing the initial public offering (IPO).

He was exhausted. But he decided to surf the Internet.

He'd always been interested in astronomy, physics, UFOs, stuff like that. As a teenager, UFO stories had intrigued him, but he'd concluded that there was no way the flying saucers, or whatever they were, could cross the immense distances of interstellar space.

But on this day he found something. It was a research paper by a man named Bernhard Haisch.

Haisch, as it happens, is a physicist who works just up the road from Firmage, at Lockheed Martin. He's also the editor of the Journal of Scientific Exploration, which often carries articles about UFOs.

The Haisch paper discussed something called the "zero-point field." This is a theoretical field of energy that permeates everything, even the "empty" spaces of the universe. Haisch asserts that what gives a piece of matter its "mass" is an electromagnetic reaction with this zero-point field. The theory is abstruse in the extreme. But if Haisch is right, then mass can, in theory, be modified and engineered. Something as seemingly fundamental as inertia might be subject to cancellation. There are implications for faster-than-light travel and spaceships that require no fuel, all sorts of fabulous notions.

Firmage was captivated by the Haisch paper and its implications. If humans could modify mass, inertia, space-time, then so could . . . the Visitors. Firmage took a printout home and stayed up late reading. He finally set his alarm for 6:10 a.m. and went to sleep.

Morning arrived. The alarm rang. He hit the snooze button.

"The next nine minute snooze changed the course of my life," he writes.

Without warning, a "remarkable being clothed in brilliant white light" appeared above him, hovering over the bed.

"Why have you called me here?" the entity asked.

Firmage, half awake and half asleep, said, "I want to travel in space."

"Why should you be granted such an opportunity?" said the entity.

"Because I'm willing to die for it," Firmage said.

And then an electric blue sphere emerged from the being and entered Firmage.

"Instantly, I was overcome by the most unimaginable ecstasy I have ever experienced, a pleasure vastly beyond orgasm."

After that, he began writing furiously. He became intellectually hyper-linked to all kinds of new and imponderable theories. He tunneled deep into the world of UFOs. He claims he has had private conversations with some of the top military leaders in America, who have confided that aliens are real. He won't say who these leaders are.

Firmage now believes that aliens get interested in a planet when the most intelligent species on that planet learns how to control gravity. The aliens couldn't possibly stand around doing nothing while humans, so raw and unfinished a species, began racing across the galaxy like teenagers on spring break.

Firmage says he'd love to be in a leadership position if formal contact with the aliens begins -- if, for example, "two years from now, we had a craft hovering over Times Square, or landing in the middle of the Super Bowl."

All roads in the Firmage universe lead to UFOs. For Firmage, the visions reported by prophets and religious figures -- including Joseph Smith, founder of the Mormon faith -- are strikingly reminiscent of modern encounters with aliens.

As Firmage journeyed deeper -- and after he began anonymously posting pieces of "The Truth" on a Web site called Project Kairos -- his position within his own company became problematic. Corey, his partner, says he was sympathetic to Firmage's position on UFOs. "There appears to be a number of data points that appear to come from a lot of credible people," Corey says.

Nonetheless, some members of the company's board were uncomfortable with Firmage's new passion, particularly after he went public with his beliefs in November. There were clients who were appalled that the head of the company was espousing views normally associated with crackpots. USWeb's stock price began to slip. The company had merged with a firm called CKS, and it was a sensitive moment. Any sign of weakness can be fatal in the computer industry. Firmage had already planned to step down as CEO, making way for an older executive, but it became clear that he had to hurry up the transition. He became the chief strategist. Eventually, even that seemed too lofty a title for someone with his beliefs, and he became a mere consultant.

His next step will be to print 100,000 copies of "The Truth" as an elegant hardback, self-published, he says, so he'll have total editorial control. This summer he'll embark on a 20-city book tour. He won't do ordinary book signings but will speak, he vows, in auditoriums and other large venues. He's thinking big all the way.

THE SEARCH

And what does Bernhard Haisch, the man behind the zero-point field, think of Joe Firmage?

"He's way out there."

He thinks Firmage is smart and wishes him luck. Haisch is open to anomalies, UFOs, government conspiracies. But he's also a scientist, and he knows that his theories about the zero-point field are nowhere close to being verified.

Moreover, a scientist would never write something called "The Truth." A scientist might write "The Theory." To approach the level of a truth, a theory must be tested, vigorously and should have the potential to be falsified. That's one of the many problems with the UFO mythology. Covert entities can't be disproved. Nor can secret government conspiracies.

Haisch says, "Because he's not a scientist, and because of his youth and his success, he's probably not applying as stringent a filter as he might."

Aliens in UFOs don't survive the violent jostling they receive when they pass through the filters of most scientists. Among those who rejected the idea that aliens have visited our planet was Firmage's hero, Carl Sagan. Firmage knows that. He has an explanation: "Sagan was not aware of zero-point physics."

The professional UFO debunker Philip Klass says of Firmage, "In terms of establishing or proving that we have ET visitors, he adds nothing."

Many scientists note that there is not a single scrap of metal that appears extraterrestrial in any laboratory analysis. "Why doesn't anyone come into my office with an ashtray or a radio knob from one of these things?" asks Seth Shostak, an astronomer at the SETI Institute, which conducts radio searches for signals from extraterrestrial civilizations, and which is loath to be associated with UFOs.

Firmage admits that 80 percent of UFO stories are nonsense. But there is truth out there on the fringes, he insists. The entire cosmos has characteristics of being conscious, Firmage believes. We are spiritual beings coming to terms with the meaning of our existence. We will someday lose our appetite for material possessions. What we will value are experiences -- like traveling in space.

He imagines what that would be like. In "The Truth," he writes:

As you ascend through the clouds, piercing beyond the lung of your world, a silence strikes every sense of your soul. Your gaze shifts from the blue light below, and you look up. A black blacker than sudden blindness hits your senses, or rather doesn't, as your eyes adjust to the silent night of heaven. And ever so gracefully, the campfires of the Cosmos begin to sparkle . . .

This is an age of searchers, of people who would figure out everything, the future, the significance of human history, the thinking of the gods. The Internet explodes with information that almost makes sense. Firmage believes in himself, and assumes that his instincts are right. His instincts tell him that change is nigh. We will understand what is happening. We will know the secrets of cosmic intelligence.

"Imagine one day we could plug our Internet into theirs," he says. "That would be cool."

If he's right, he'll be vindicated. No one will mock the UFO CEO anymore. On the day of unambiguous alien contact, he will be undeniably credible. A winner once again.

But what if he's wrong?

"If I go down, I'll take this belief system with me."

Another bold declaration, but perhaps his least plausible assertion. The aliens are durable creatures. They were here in spirit before Joe Firmage, and they will be here in spirit when he is gone.

CAPTION: Joe Firmage and the firmament: The 28-year-old computer executive who amassed a fortune has abandoned Silicon Valley to pursue his quest for The Truth.

CAPTION: Joe Firmage's book "The Truth" is posted chapter and verse on the World Wide Web.