BERLIN -- A helicopter flies over an empty stretch of desert. A cluster of buildings comes into the view on the horizon. As the pilot steers towards it, one of the passengers comments cynically: "Great architecture . . . it'll photograph great."

A second passenger, looking at the complex of whitewashed concrete blocks, asks what he means.

The man explains: "Because it has no projections . . . no antennas, no spikes, no things poking up. People are afraid of spikes and antennas. There are studies. But a building that's plain and square like this, and white -- perfect colour choice, associations to virginal, hospital, cure, pure -- a building like this, they don't care."

Today's reader could be forgiven for placing this account in Iraq, imagining the men to be members of the UN weapons-inspection team.

In fact, the scene is taken from best-selling American author Michael Crichton's latest book Prey, which hit bookstores yesterday. Appetite-whetting excerpts from it, such as the helicopter sequence, have been landing on the book's Web site for several weeks.

Crichton, arguably the most popular science-fiction author of the day, knows that the most frightening enemy is not a far-away Saddam Hussein, but something in our midst, to which we can attach no name or face.

The 60-year-old author denies, however, that his intention is to titillate or terrify. In an interview posted on the Prey Web site, Crichton claims that he was drawn to write the book by an interest in three emergent areas in science: distributed programming, biotechnology and nanotechnology.

"Just as war is too important to be left to the generals, science is too important to be left to the scientists," writes Crichton.

Meanwhile, publisher Harper Collins is marketing the book with the slogan: "You won't see them until they swarm and you become PREY," and apocalyptically advising Crichton fans to order their copy today, "Because time is running out."

In Prey, a group of scientists at Xymos Molecular Manufacturing have conducted an experiment that didn't go according to plan. A cloud of particles -- self-assembling, self-reproducing, self-sustaining molecules -- have escaped from a lab in the middle of the Nevadan desert. The molecules have been programmed as predators.

German physicist Wolfgang Heckl, recently in Berlin for a conference on science and the media, sighs heavily at the mention of the Crichton book.

"I'm all for interesting young people in science," says Heckl, who won this year's Communicator Award from Germany's largest science foundation for his ability to render science intelligible to lay folk. "And Jurassic Park did wonders for biology and paleontology. But scientifically unreasonable scenarios like the ones in Prey could really harm the field."

"The field" for Heckl is nanoscience and he is one of its leading lights. Nano is the measure 10 to the minus nine or, in Heckl's terms: In terms of size, a football to the planet Earth is roughly the same relation as that of a nano-particle to a football.

Nanotechnology, which involves manipulating atoms at the nano-level, was established as a discipline in 1959. It took a giant leap forward in 1986 when Gerd Binnig won the Nobel Prize in physics for his invention of the scanning tunnel microscope. Heckl, who worked with Binnig at the IBM Research Lab in Switzerland, twinkles when he talks about the microscope. He describes it as a kind of elephant's trunk that has a probe at the end that enables molecules to be extracted, taken apart and re-assembled at the nano-level.

"It offers breathtaking new capabilities," says Heckl, who has earned a place in the Guinness Book of Records for having bored the smallest hole in the world. "I can synthesize a new molecule, look at the thing and realize that I don't know what I've created."

Which is something like the starting point of Crichton's tale.

"The scenario in Prey is highly artificial," Heckl explains, "but it belongs to an archetypal model of exponential growth." A kind of growth that tends to make the general public nervous. Like the atomic bomb and biological warfare, which are both the exponential results of micro-processes, Crichton's scenario involves molecules that assemble themselves, multiply and reproduce exponentially using a combination of bio- and nanotechnological methods.

In order to support this growth, they need energy, which puts them in direct competition with man for food. And as the food supply gets scarce, the nano-critters develop a taste for mankind itself.

Within the field, rampant molecules such as the ones in Prey are called "grey goo." The scenario that Crichton describes is old hat to nano-physicists.

Heckl has joined with colleagues from the American Association of Science to prepare a press statement that will coincide with the book's release "to explain how the book should be interpreted." Which sounds a bit like exegesis.

"We have to take this seriously," says Heckl, who did his postdoctoral work at the University of Toronto in 1989. "If enough senators in the U.S. get phone calls from their constituents saying, 'I just read Prey and I'm scared,' it could have a real impact on our funding. Nanoscience is just in its infancy. We can't afford to be cut off."

Nanotechnology has potentially very broad applications, from molecular submarines trained to kill medical viruses to micro-storage devices in computers to "miracle products" like self-cleaning window glass or stain-resistant fabrics.

It could also be used to explain the origin of the life. Heckl's current research is focused on crystals, the most primitive ordered systems. Together with his colleague Stephen Sowerby from New Zealand, he is examining the possibility that a thin, very hot crystalline layer may have offered the template on which DNA originally self-organized itself, giving rise to life for the first time.

"Life is nothing more than the gradual creation of order," says the 44-year-old scientist, as though nothing could be more obvious, "and through the high resolution scanning tunnelling microscope, we can watch part of this process in the lab."

The microscope uses nanotechnology in the form of molecular self-assembly to create bio-machines that are capable of replicating themselves through a code and enzyme. Much like the things that are unleashed in Prey.

"Our experiments lead us to the conclusion that at the beginning, life was not cooked in a primordial soup, but baked on a hot plate."

As Heckl savours the thought, it becomes clear what he and his colleagues stand to lose if Crichton's book caused a public hysteria that in turn influenced the funding climate.

Crichton's books reach a much wider audience than just hard-core sci-fi fans. Two of them -- The Andromeda Strain and Jurassic Park -- have been made into Hollywood blockbuster films and the motion-picture rights to Prey have already been bought by Twentieth Century Fox. This fall, Crichton partnered with SEGA to develop a new video game, scheduled for release in 2004.

Nonetheless, it's hard to imagine that a piece of popular fiction could prevent Heckl from exploring the world's primal hot plate, or from tinkering with his mobile grid microscope, which will be used to scour surface sediments on Mars.

But Heckl is wary, and cites the most spectacular incident of fiction overtaking science. On Oct. 30, 1938, at 8 p.m., Orson Welles broadcast a radio adaptation of the H. G. Wells short story War of the Worlds. The actor did a fine job of dramatizing the tale of a Martian invasion of Earth -- he was so effective that roughly one million of the estimated 12-million listeners believed the broadcast. The panic that ensued set a benchmark in broadcast history, spawned the U.S. Civil Defence Program and was cited by Adolf Hitler as evidence of American stupidity.

Without a doubt, the American public's extreme reaction to the broadcast -- and its success as a drama -- was related to a general sense of global instability and what was, at that point, a fear of imminent war in Europe.

Which might suggest that the image of a helicopter hovering over mysterious white buildings on an empty desert is indeed the right image with which to market Prey.