The Prophet had arrived in the city. He had come by bicycle from far away. The Prophet had long hair and an unkempt beard such as befits a prophet, but no robe nor sandals. Just old jeans and running shoes and a faded T-shirt on which read: YOU CANNOT BUY THE FUTURE.

The Prophet prophesied at streetcar stops, on pedestrian walkways, in the marketplace, in the exhibition hall, on railroad platforms and in supermarkets. But from all those places he was eventually driven away.

He had a lot to say, but nothing very amusing. He predicted catastrophes and accidents. He said that the world's cities would soon fall into ruin and desolation and would disintegrate into clouds of dust. And that the populace was threatened by comets and wars and floods and hurricanes and mudslides and drought and thirst and Kreutz-Ebbing's Disease.

No, that was no fun at all, and few people cared to listen to the Prophet. Some began to weep, some laughed, many became irritated. But still there were a few who endured until the end of each sermon. They followed the Prophet from country to country and were known as disciples.

Lydia happened to hear the Prophet's predictions when she went with Sulevi to a large shopping mall to buy cocoa and milk and oranges and chocolate cookies. The Prophet stood on the walkway between a hosiery boutique and a nail studio and preached. On either side of him stood two young disciples, like an honor guard.

A product demonstrator was demonstrating new products opposite the Prophet, on the other side of the walkway. Lydia and Sulevi heard what both were saying.

The product demonstrator held up a small object. He said it was a genuine, original Neurophone.

"Find out what the Neurophone can do for you!" the product demonstrator said. "The electrodes and audio receivers are included. Now at a bargain price! Come closer and hear with your own ears!"

"What's a Neurophone?" Lydia whispered.

"Come closer!" the Prophet also commanded Lydia and Sulevi and a retired lady and three third-grade boys. "Hear what the future will bring! Learn how you yourselves can change it!"

The product demonstrator raised his voice and cried, "I have here another revolutionary technological invention!"

"Technology," said the Prophet, "and human greed have led us astray. Everything that mankind has made, all his inventions and machines, everything that is his pride and joy will be destroyed. Unless-"

And the Prophet fell silent and looked expectantly at his little audience.

"Unless what?" asked a second-grader finally.

"You tell them," the Prophet urged one of his disciples. And the disciple cleared his throat and said shyly: "Unless people change."

"Exactly!" the Prophet said. "People must change, and change greatly. But we do not want to change, therefore we must first want the desire. That is the hardest thing. If our desires change, everything else will follow automatically."

"Boing's springy athletic shoes!" the product demonstrator said. "Notice the flexible heel!"

"Learn to change. Teach yourselves to desire the right desires," the Prophet said.

Sulevi listened to the Prophet very attentively. Lydia began to worry a little at how intently Sulevi was listening.

"Let's go now," Lydia whispered. On the other side of the walkway the product demonstrator was saying, "Run twice as fast! Wear the Boing springy shoes, they'll give you the speed of a panther!"

"No," Sulevi said, "he's only telling the truth."

"Which one?" Lydia asked.

The product demonstrator had already switched to a third product. He said: "This device is revolutionary! Come and test it for yourselves! This digital helmet will massage your cranium and free you from needless tension."

But the Prophet said that the future would not come if people did not change. At the same time he looked into the eyes of each of his listeners in turn.

"How must we change?" Lydia heard Sulevi say.

"You must forget yourselves," the Prophet said. "You must live simply. You must renounce everything that is nonessential."

But how do we know what's nonessential? Lydia thought. And how can we forget ourselves when we have to live inside ourselves all the time?

She looked at the new watch that she had received as a birthday present and on which her name was engraved. She felt that she needed it, but did that mean that the watch was truly essential?

The product demonstrator said, "Here is the ultimate Father's Day gift. Truly a specialty: a pistol-shaped TV remote control!"

"I'd like to travel like the Prophet," Sulevi said, "from city to city."

In his eyes was a faraway look, a look of longing.

"You can't do that," Lydia said, poking him in the ribs almost angrily. "You're still too young. And I'd miss you."

"You could come along," Sulevi said.

"No, I couldn't," Lydia said. "I don't particularly care for the Prophet, and I don't want to leave Father."

Just then a security guard approached and told the Prophet that he would have to preach his sermon somewhere else. "Go outside to speak," the man said. "It's not appropriate here."

Then the product demonstrator was able to make his voice heard again. He showed them a small, ugly bag.

"This," he said, "is the world's most effective flytrap. It may look like just a little bag, but it can catch up to 20,000 flies!"

What on earth would anyone do with 20,000 flies? Lydia wondered to herself.