I MAY NEVER BE ABLE to publish the whole story about the conspiracy. The danger is too great. I am not so worried about myself, but my friends could be hurt and complete disclosure, especially at this time, would probably make it impossible for the key person in the affair to carry out his fight against the intelligence agencies. They already have him in prison. And one misstep by anybody, even by someone indirectly involved like myself, could give them reason to put him away for good.

And so I can only tell part of the story. Specifically, I can tell about that mad half-hour when I learned the real reason for the great snows and saw the aftermath of the "accident" that almost killed a man in Harvard Square.

It happened almost a year ago, and at the time I did not realize that the separate events of that half-hour were related, integrated into the amazing whole. I only thought to raise my camera at the rest.

I had been wandering through East Cambridge with a camera, looking for urban landscapes and trying to feel like an artist. But after a couple of hours I had found nothing that would get me into the Museum of Modern Art and snow clouds were soaking up what was left of the late afternoon light. I decided to head home.

As I waited for the bus that would take me up Cambridge St. to Harvard Square, it began to snow--a sudden burst, the kind that blows fiendishly hard little snow crystals into your face no matter how deeply you hide your head in the hood of your coat.

I stood in the stinging cold for 15 minutes before the bus came. It was crowded, but I managed to find a seat in the back. It was a good seat from which I could easily eavesdrop on four or five different conversations. For a while I listened to an elderly woman complain to the young man beside her about the constant snow. It was the worst winter she could remember, and today she was especially angry because the weather had forced her bridge club to cancel its weekly party.

The man nodded in sympathy as she said, "I wish the rest of the girls had the spirit to fight this crazy stuff. Look, I don't let it stop me. I go out every day." And she hoisted a little bag of groceries as proof.

The man was about to reply when, bam! a well-thrown snowball smashed into the window about six inches from the woman's ear. Bam! Bam! Two more hit the bus further up. Kids on their way home from school had us pinned down at a stoplight.

They were good. It was a well-planned attack, and they were showing no mercy. They were slinging big, juicy iceballs and aiming right for the windows.

By the time the light changed we had taken more than a dozen direct hits, and everyone on board was cringing away from the windows. The old lady peered nervously at the glob of wet snow still sticking to the outside of her own window and clutched her groceries to her breast. She had been lucky this time. The window had saved her.

There was a lull in the conversation for a while after the attack. And it was the lull that enabled me to overhear that first phrase.

"Weather warfare."

I had just been sitting there observing how the snow melted off my shoes and made a little rivulet on the floor of the bus, when those words took hold of me.

"Weather warfare."

And then, "Enhanced storms...."

Someone was whispering in the seat behind me. It was a passionate whisper, "Don't you see? It's the only possible explanation."

The whisper went on, "You have to believe me. I swear it's true. I saw the satellite photos of the cloud formation. The Weather Bureau would never admit it, but it's impossible to get those kinds of clouds around here at this time of year. It's too cold for them to form naturally. So it had to be an enhanced storm--nukes in the upper atmosphere. That's the only way we could have gotten the blizzard that we did. They had to make it."

It was madness.

I cautiously glanced over my shoulder to see who was behind me. I expected that it would probably be one of the loons that you grow accustomed to seeing around Harvard Square, one of those hypersensitive geniuses who, instead of becoming Einsteins, had slipped the other way, taking one too many acid trips back in 1965, and wandering around the Square ever since, babbling stray mathematical formulae on the street corners. Maybe it would even be Dryer Man, the guy with the electric hair who likes to sit on those big industrial dryers in the laundromat and get off on the vibes.

I halfway hoped that it would be him. Then madness would explain madness, and my own fragile world would still be intact.

But the two guys behind me did not seem to be loons. They were no more eccentric than it is fashionable to be in Cambridge. And they were very serious about their discussion.

It was indeed a topic to be serious about. They were talking about the Great Blizzard that had overwhelmed New England a few weeks before, and one guy believed he now understood where all the snow had come from.

"And what about the radiation? Did you hear about that? No, of course not. They covered that up, too. But I took snow samples. I have the data.

"Did you notice how the snow glowed? Late that first night when it was still falling I went outside to watch. And I saw it: the whole sky was filled with green light.

"And then there were the epidemics. The flu and the viruses started to hit people right after the blizzard. The radiation weakened their resistance."

An enhanced storm created by the carefully planned detonation of nuclear devices in the upper atmosphere. It was a wild idea, but the guy certainly believed it.

It was all part of a global conspiracy involving the power centers of the industrialized world. Both the CIA and the KGB were in on it. And so were many of the multinationals. And the Trilateral Commission, too.

The plan was to conduct a comprehensive program of weather warfare to alter world climate patterns. They were going to deprive the underdeveloped world of climates suitable for agriculture. Starve them out. Make them grateful to trade their raw materials with the industrialized nations. Make the third world willing to give anything for a little grain.

And the powers could do it, too. The intelligence agencies had the covert capabilities, and the corporations had the technology and the necessary finance capital. They both had the global organizational structures to implement the plan.

This was the biggest operation they had ever attempted. In the past they had made the mistake of not acting boldly enough. But not any more. No more sloppy, half-assed affairs like Chile. This time the game was for all the marbles.

You could already begin to see the results of the program. All over the world the weather was more bizarre than anyone could remember. There were unusual storms, massive rains, horrible droughts. The deserts were expanding into the farmlands of millions of people.

"Can you imagine the consequences?" the guy asked. "In the end nobody will be safe. They'll get us all."

He was whispering very emotionally as he explained all this to his friend. Like a man who had found Truth, he was compelled to spread the word. And like a good evangelist he had skillfully woven myth and fact, vision and reality, into a web so entangled that you could never be really sure of anything.

What if it were true? What if even just a part of it were true? There were so many possibilities, so many ways that such conspiracies could grow in the modern world with the systems of power so unaccountable and so intertwined, not just on the surface but intertwined deeply on many unpredictable levels.

There were always stories about how the former head of the intelligence agency was now on the board of the corporation whose president had a brother at the World Bank who arranged billion-dollar loans so that a third world nation with a new right-wing regime propped up by the intelligence agency could finance a construction project proposed by the corporation.

Under such circumstances you had to admit that almost anything was possible.

The bus arrived in Harvard Square and I stepped back out into the snow. It was coming down very hard, but there were a lot of people around, a crowd milling on the sidewalk.

I saw the rescue truck from the fire department parked in the street. And then I saw the body on the pavement in the middle of the crowd. It was a young man with blood pouring from his head.

Nobody seemed to know what had happened to him--or if they did know they refused to say. Was he a drunk who fell and cracked his head on the curb? Or was he attacked?

The rescue squad put an emergency dressing on the wound and carried the man to their truck on a stretcher. I stood there watching as the truck drove off and was swallowed up by the swirling snow.

The crowd of people dispersed, and all that was left was some blood and stray pieces of gauze dressing on the sidewalk. But the snow was quickly covering up that, too.