Hari Seldon and Dors Venabili left the University grounds at 0300. Seldon realized that Dors had to be the leader. She knew Trantor better than he did-two years better. She was obviously a close friend of Hummin (how close? the question kept nagging at him) and she understood his instructions. Both she and Seldon were swathed in light swirling docks with tight-fitting hoods. The style had been a short-lived clothing fad at the University (and among young intellectuals, generally) some years back and though right now it might provoke laughter, it had the saving grace of covering them well and of making them unrecognizable-at least at a cursory glance.

Hummin had said, “There’s a possibility that the event Upperside was completely innocent and that there are no agents after you, Seldon, but let’s be prepared for the worst.”

Seldon had asked anxiously, “Won’t you come with us?”

“I would like to,” said Hummin, “but I must limit my absence from work if I am not to become a target myself. You understand?”

Seldon sighed. He understood.

They entered an Expressway car and found a seat as far as possible from the few who had already boarded. (Seldon wondered why anyone should be on the Expressways at three in the morning-and then thought that it was lucky some were or he and Dors would be entirely too conspicuous.)

Seldon fell to watching the endless panorama that passed in review as the equally endless line of coaches moved along the endless monorail on an endless electromagnetic field.

The Expressway passed row upon row of dwelling units, few of them very tall, but some, for all he knew, very deep. Still, if tens of millions of square kilometers formed an urbanized total, even forty billion people would not require very tall structures or very closely packed ones. They did pass open areas, in most of which crops seemed to be growing-but some of which were clearly parklike. And there were numerous structures whose nature he couldn’t guess. Factories? Office buildings? Who knew? One large featureless cylinder struck him as though it might be a water tank. After all, Trantor had to have a fresh water supply. Did they sluice rain from Upperside, filter and treat it, then store it? It seemed inevitable that they should. Seldon did not have very long to study the view, however.

Dors muttered, “This is about where we should be getting off.” She stood up and her strong fingers gripped his arm.

They were off the Expressway now, standing on solid flooring while Dors studied the directional signs.

The signs were unobtrusive and there were many of them. Seldon’s heart sank. Most of them were in pictographs and initials, which were undoubtedly understandable to native Trantorians, but which were alien to him.

“This way,” said Dors.

“Which way? How do you know?”

“See that? Two wings and an arrow.”

“Two wings? Oh.” He had thought of it as an upside-down “w,” wide and shallow, but he could see where it might be the stylized wings of a bird. “Why don’t they use words?” he said sullenly.

“Because words vary from world to world. What an ‘air-jet’ is here could be a ‘soar’ on Cinna or a ‘swoop’ on other worlds. The two wings and an arrow are a Galactic symbol for an air vessel and the symbol is understood everywhere. Don’t you use them on Helicon?”

“Not much. Helicon is a fairly homogeneous world, culturally speaking, and we tend to cling to our private ways firmly because we’re overshadowed by our neighbors.”

“See?” said Dors. “There’s where your psychohistory might come in. You could show that even with different dialects the use of set symbols, Galaxy-wide, is a unifying force.”

“That won’t help.” He was following her through empty dim alleyways and part of his mind wondered what the crime rate might be on Trantor and whether this was a high-crime area. “You can have a billion rules, each covering a single phenomenon, and you can derive no generalizations from that. That’s what one means when one says that a system might be interpreted only by a model as complex as itself.-Dors, are we heading for an air-jet?”

She stopped and turned to look at him with an amused frown. “If we’re following the symbols for air-jets, do you suppose we’re trying to reach a golf course? Are you afraid of air-jets in the way so many Trantorians are?”

“No, no. We fly freely on Helicon and I make use of air-jets frequently. It’s just that when Hummin took me to the University, he avoided commercial air travel because he thought we would leave too clear a trail.”

“That’s because they knew where you were to begin with, Hari, and were after you already. Right now, it may be that they don’t know where you are and we’re using an obscure port and a private air-jet.”

“And who’ll be doing the flying?”

“A friend of Hummin’s, I presume.”

“Can he be trusted, do you suppose?”

“If he’s a friend of Hummin’s, he surely can.”

“You certainly think highly of Hummin,” said Seldon with a twinge of discontent.

“With reason,” said Dors with no attempt at coyness. “He’s the best.”

Seldon’s discontent did not dwindle.

“There’s the air-jet,” she said.

It was a small one with oddly shaped wings. Standing beside it was a small man, dressed in the usual glaring Trantorian colors.

Dors said, “We’re psycho.”

The pilot said, “And I’m history.”

They followed him into the air-jet and Seldon said, “Whose idea were the passwords?”

“Hummin’s,” said Dors.

Seldon snorted. “Somehow I didn’t think Hummin would have a sense of humor. He’s so solemn.”

Dors smiled.

There were just two seats behind the compact pilot compartment and when Seldon sat down on padding that gave slowly beneath him meshed fabric came forward to encircle his legs, waist, and chest and a hood came down over his forehead and ears. He felt imprisoned and when he turned to his left with difficulty-and only slightly-he could see that Dors was similarly enclosed.

The pilot took his own seat and checked the controls. Then he said, “I’m Endor Levanian, at your service. You’re enmeshed because there will be a considerable acceleration at lift-off. Once we’re in the open and flying, you’ll be released. You needn’t tell me your names. It’s none of my business.” He turned in his seat and smiled at them out of a gnomelike face that wrinkled as his lips spread outward. “Any psychological difficulties, youngsters?”

Dors said lightly, “I’m an Outworlder and I’m used to flying.”

“That is also true for myself,” said Seldon with a bit of hauteur.

“Excellent, youngsters. Of course, this isn’t your ordinary air-jet and you may not have done any night flying, but I’ll count on you to bear up.”

He was enmeshed too, but Seldon could see that his arms were entirely free.

A dull hum sounded inside the jet, growing in intensity and rising in pitch. Without actually becoming unpleasant, it threatened to do so and Seldon made a gesture as though to shake his head and get the sound out of his ears, but the attempt to do so merely seemed to stiffen the hold of the head-mesh. The jet then sprang (it was the only verb Seldon could find to describe the event) into the air and he found himself pushed hard against the back and bottom of his seat.

Through the windshield in front of the pilot, Seldon saw, with a twinge of horror, the flat rise of a wall-and then a round opening appear in that wall. It was similar to the hole into which the air-taxi had plunged the day he and Hummin had left the Imperial Sector, but though this one was large enough for the body of the jet, it certainly did not leave room for the wings. Seldon’s head turned as far to the right as he could manage and did so just in time to see the wing on his side wither and collapse. The jet plunged into the opening and was seized by the electromagnetic field and hurtled along a lighted runnel. The acceleration was constant and there were occasional clicking noises that Seldon imagined might be the passing of individual magnets.