“PRISONERS all asleep,” reported the soldier on duty. “Everything quiet,” said the soldiers who checked the

slaves' quarters a little later. “Sleeping like babies.'

“All well,” the Captain of the Guard reported to the Overlord.

“Was the new medication effective?”

“Seems to have worked like a dream, my Lord.”

“Splendid. Your men may retire, Captain. Their sleep is programmed.”

“I would still like to leave a guard at the entrance to the tunnel to Outside, my Lord.”

“You really think that's necessary?” “There may be more savages outside.”

“All right. Six men be enough? Leave me their names.”

The Captain saluted smartly, placed a list of names on the desk, turned on his heel and left.

Alone in his office the Overlord looked at the list of guards to remain on duty, ripped it across and tossed the pieces into his waste basket. The Captain would not know until it was too late that he had no intention of deleting the sleep program for these six guards from the computer. He glanced up at the clock. Nine-forty-five. In fifteen minutes the Ark would be asleep.

He walked down the empty corridor to the Central Computer, circuit diagrams in his hand. The door opened to his handprint. It was now nine-fifty. He looked around the familiar room. Here in this place was the accumulated know- ledge of the world. In one small room. But then the genius of Michelangelo, or of Einstein or Madame Curie were contained in braincases far far smaller. Perhaps after all the computer was not so great a miracle as the mind of the person who first thought of it.

Ten at last. He strode from the room and along the sleeping corridors of Ark One. He keyed open a particular storage area on level Four. As the door slid open Ruth jumped to her feet.

“ Is it time at last?”

“Yes. Do you know what you must do?”

Ruth nodded. She slipped by him and ran down the corridor. She took the elevator up to the first level and hurried to the perimeter of the West Quad. There she stopped abruptly. On either side of the storage room, behind which was the passage to outside, stood a soldier.

Feet slightly apart, shoulders braced against each door jamb, heads bowed slightly over their guns, they looked like toys in their bright red uniforms. Ruth flattened herself behind a pillar and waited, her heart thumping.

What's wrong? They shouldn't be here.