"I keep forgetting your appet.i.te. All right, we'll eat as soon as we find a restaurant."

They found one a block away. It was easy enough to walk there. It was stopping that was hard. Marcus made his way to the side of the street and hauled Wilbur in out of the stream of pedestrians. Inside there was one vacant table which they promptly took, oblivious to the glares of those who were not so fast afoot.

Marcus studied the menu at length. To his disappointment, there was no lot 219 steak listed. Instead there were two other choices, a lot 313 and a miscellany steak. Marcus looked up to see that his son had already dialed his order. Questioning revealed that Wilbur had missed his afternoon snack and thought that a full portion of one steak and half of the other would compensate for his fast. "Vegetables, too," said Marcus.

"Pa, you know I don't like that stuff."

"Vegetables," said Marcus, watching to make sure his son selected a balanced diet. After deliberation, he decided on a high protein vegetable plate for himself, though ordinarily he liked meat. He couldn't get that idea out of his mind.

The low rectangular serving robot scurried up and began dispensing food with a flurry of extensibles. Marcus noted that the steaks were identical with those served in the hotel. "Waiter, what is the origin of those steaks?"

"The same as all meat. Hygienically grown in a bath of nutrients that supply all the necessary food elements. Trimmed daily and delivered fresh and tender, ready for instant preparation."

"I'm familiar with the process," snapped Marcus, wincing as his son chewed the gray, watery substance. "What I asked was the origin, the ultimate origin. From what animals were the first cells taken?"

"I don't know. No other protein source is so free from contamination."

"Will the manager know?"

"Perhaps."

"Tell him I would like to see him."

"I'll pa.s.s the request along. But it won't do any good. The manager can't come. It's a robot attached to the building."

"Then I'll go to it," said Marcus, rising. "Keep the food warm. How do I get there?"

"The manager shouldn't be disturbed," said the robot as it placed thermoshields over the food. "It's the small room to the rear, at the right of the kitchen."

Marcus found the place without difficulty. The manager lighted up as he came in. The opposite wall blinked and a chair swung out for him.

"Complaint?" said the manager hollowly. The manager was hollow.

"Not exactly," said Marcus, repeating his request.

The manager meditated briefly.

"Are you an Outer?"

"I am."

"I thought so. Only Outers ask that question. I'll have to find out some day."

"Make it today," said Marcus.

"An excellent thought," said the manager. "I'll do it. But this is a chain restaurant and so you'll have to wait. If you don't mind the delay, I'll plug in one of our remote information banks."

Marcus did mind delay, but it was worse not knowing. He waited.

"I have it," said the robot after an interval. "There is great difficulty feeding a city this large. In fact, there is with all of Earth--it's greatly overpopulated."

"So I understand," mumbled Marcus.

"The trouble began forty-five or fifty years ago with the water supply,"

said the robot. "It was sanitary, but there was too great or not great enough concentration of minerals in it. Information isn't specific on this point. The robots in control of the tanks found that beef, pork, lamb and chicken in all their variety would not grow fast enough. Many tanks wouldn't grow at all.

"The robots communicated this fact to higher authorities and were told to find out how to correct the situation. They investigated and determined that either the entire water-system would have to be overhauled, or a new and hardier protein would have to be developed.

Naturally, it would require incalculable labor to install a new water-system. They didn't recommend it."

"Naturally," said Marcus.

"The situation was critical. The city had to be fed. The tank robots were told to find the new protein. Resources were thrown open to them that weren't hither-to available. In a short time, they solved the problem. About half of the tanks that were not growing properly were cleaned out and the new protein placed in them. The old animal name system was outmoded so the new lot number system was devised and applied to every tank regardless of its ultimate origin."

"Then n.o.body has any idea what they're eating," said Marcus. "But what was that new protein? That's what I want to know."

"It was hardy. It came from the most adaptable creature on Earth," said the robot. "And there was another factor in favor of it. The flesh of all mammals is nearly the same. But there are differences. The ideal protein for a meat-eating animal is one which exactly matches the creature's own body, eliminating food that can't be fully utilized."

Marcus closed his eyes and grasped the arm of the chair.

"Do you feel ill?" inquired the managing robot. "Shall I call the doctor? No? Well, as I was saying, there was already a supply of animal tissue on hand. It was this that the robots used. It's funny that you're asking this. Not many people are so curious."

"They didn't care," snarled Marcus. "As long as they were fed, they didn't ask what it was."

"Why should they?" asked the robot. "The tissue was already well adapted to growth tanks. Scrupulously asceptic, in no way did it harm the original donors who were long since dead. And there was little difference in the use of it, anyway. No one would hesitate if he were injured and needed skin or part of a liver or a new eye. This was replacement from the inside, by a digestive process rather than a medical one."

"The robots took tissue from the surgery replacement tanks," said Marcus. "Do you deny it?"

"That's what I've been telling you," said the robot. "A very clever solution considering how little time they had. However only about half of the tanks had to be replaced."

"Cannibals," said Marcus, nearly destroying the chair as he hurled it away from him.

"What's a cannibal?" asked the robot.

But Marcus wasn't there to answer. He went back to the restaurant, under control by the time he reached the table. He couldn't tell Wilbur because Wilbur had finished eating except for the vegetables which were mostly untouched. Marcus sat down and took the shields off the food, looking at it gloomily.

"Pa, aren't you going to eat?" asked Wilbur.

"As soon as I get my breath back," he said. It wasn't bad when he ate, but the mere thought of food was distasteful. He glanced sternly at his son. "Wilbur, hereafter you may not order meat. As long as we are on Earth, you will ask for eggs."

"Just eggs?" said Wilbur incredulously. "Gee, they're real expensive here. Anyway, I don't like them without a rasher of--"

"Eggs," said Marcus. Another thought occurred to him. "Sunny-side up. No cook can disguise that."

The sky was dark when they left the restaurant. After work, traffic had abated and the entertainment rush hadn't come on the streets, which were now curiously silent and deserted. Marcus caught sight of the tall spire of Information Center glistening against the evening sky.