She held him back. "No, no! There's another one."

The second Khor, entering the clearing, looked up at the sky. The first came from the hut with a flaring cresset on a pole, and the second ran quickly to the hut in which Reith and Zap 210 were concealed. The first took no notice. As the Khor entered Reith struck hard, ignoring all precepts of gallantry; in this case male and female were all the same. The Khor fell and lay limp. Reith jumped forward; the Khor was male. Reith stripped off his cape, tied his hands and feet with sandal thongs and gagged him with the sleeve of his black coat. With Zap

210's help he dragged the man behind the rack of masks. Here Reith made a quick search of the limp body, finding a pair of iron darts, a dagger and a soft leather pouch containing sequins, which Reith somewhat guiltily appropriated.

Zap 210 stood by the door gazing out in fascination. The first to come had been a woman. Wearing a woman-mask and a white frock, she stood by the cresset which she had thrust into a socket near the central platform. If she were perplexed by the disappearance of the man who had entered the hut she gave no sign.

Reith looked forth. "Now: while there's only one woman-"

"No! More come."

Three persons slipped separately into the clearing, going to the other three huts. One, in a woman-mask and white gown, emerged with another cresset which she placed in a socket and stood quietly like the first. The other two now came forth, wearing man-masks and white gowns like those of the women. They went to the central platform and stood near the women, who made no movement.

Reith began to understand something of the purpose of the sacred grove. Zap 210 stared forth in fascination.

Reith became highly uneasy. If events proceeded as he suspected, she would be shocked and horrified.

Three more persons appeared. One came to the but where Reith and Zap 210 waited; Reith tried to deal with him as he had the other; but this time the blow was glancing and the man fell with a startled grunt. Reith was instantly upon him and shut off his breath until he fainted. Using sandal thongs and cape as before he tied and gagged the Khor and again robbed the man of his pouch. "I regret becoming a thief," said Reith, "but my need is far greater than yours."

Zap 210, standing by the door, gave a startled gasp. Reith went to look. The women-now there were three-had disrobed to stand nude. They began to sing, a wordless chant, sweet, soft, insistent. The three in the man-masks began a slow gyration around the platform.

Zap 210 muttered under her breath: "What are they doing? Why do they reveal their bodies? Never have I seen such a thing!"

"It is only religion," said Reith nervously. "Don't watch. Go lie down. You must be very tired."

She gave him a lambent look of wonder and distrust. "You don't answer my question. I am very embarrassed. I have never seen a naked person. Are all the folk of the ghaun so-so boisterous? It is shocking. And the singing: most disturbing. What are they planning to do?"

Reith tried to stand in front of her. "Hadn't you better sleep? The rites will only bore you."

"They don't bore me! I am astounded that people can be so bold! And look! The men!"

Reith took a deep breath and came to a desperate decision. "Come back here." He gave her a female mask. "Put that on."

She jerked back aghast. "What for?"

Reith took a man-mask and fitted it over his face. "We're leaving.„

"But-" She turned a fascinated look toward the platform.

Reith pulled her back around, fitted one of the Khor hats on her head, arranged the other on his own.

"They'll certainly see us," said Zap 210. "They'll chase us and kill us."

"Perhaps so," said Reith. "Nevertheless we'd better go." He looked around the clearing. "You go first. Walk behind the hut. I'll come after you."

Zap 210 departed the hut. The women at the platform chanted with the most compelling urgency; the men stood nude.

Reith joined Zap 210 behind the hut. Had they been noticed? The chanting continued, rising and falling. "Walk out into the grove. Don't look back."

"Ridiculous," muttered Zap 210. "Why shouldn't I look back?" She marched toward the forest, with Reith twenty feet behind her. From the but came a wild scream of fury. The chanting stopped short. There was stunned silence.

"Run," said Reith. Through the sacred grove they fled, throwing away the hats and masks. From behind came calls of passionate fury, but deterred perhaps by their nudity, the Khor offered no pursuit.*

Reith and Zap 210 came to the edge of the grove. They paused to catch their breath. Halfway up the sky the blue moon shone through a few ragged clouds; elsewhere the sky was clear.

Zap 210 looked up. "What are those little lights?"

"Those are stars," said Reith. "Far suns. Most control a family of planets. From a world called Earth, men came: your ancestors, mine, even the ancestors of the Khor. Earth is the world of men."

"How do you know all this?" demanded Zap 210.

"Sometime I'll tell you. Not tonight."

They set off across the downs, walking through the starry night, and something about the circumstances put Reith in a strange frame of mind. It was as if he were young and roaming a starlit meadow of Earth with a slim girl with whom he had become infatuated. So strong became the dream, or the hallucination, or whatever the nature of his mood, that he groped out for Zap 210's hand, where she trudged beside him. She turned him a wan uncomplaining glance, but made no protest: here was another incomprehensible aspect of the astounding ghaun.

So they went on for a period. Reith gradually recovered his senses. He walked the surface of Tschai; his companion- He left the thought incomplete, for a variety of reasons. As if she had sensed the alteration of his mood Zap 210 angrily snatched away her hand; perhaps for a space of time she had been dreaming as well.

They marched on in silence. At last, with the blue moon hanging directly above, they reached the sandstone promontory, and found a protected niche at the base.

Wrapping themselves in their cloaks, they huddled upon a drift of sand ... Reith could not sleep. He lay looking up at the sky and listening to the sound of the girl's breathing. Like himself, she lay awake. Why had he felt so urgently compelled to flee the Khor grove at the risk of pursuit and death? To protect the girl's innocence? Ridiculous. He looked to find her face, a pale blotch in the moonlight, turned in his direction.

"I can't sleep," she said in a soft voice. "I am too tired. The surface frightens me."

"Sometimes it frightens me," said Reith. "Still, would you rather be back in the Shelters?"

As always she made a tangential response. "I can't understand what I see; I can't understand myself ... Never have I heard such singing."

"They sang songs which never change," said Reith. "Songs perhaps from old Earth."

"They showed themselves without clothes! Is this how the surface people act?"

"Not all of them," said Reith.

"But why do they act that way?"

Sooner or later, thought Reith, she must learn the processes of human biology.

Not tonight, not tonight! "Nakedness doesn't mean much," he mumbled. "Everyone has a body much like everyone else's."

"But why should they wish to show themselves? In the Shelters we remain covered, and try to avoid 'boisterous conduct.' "

"Just what is this 'boisterous conduct'?"

"Vulgar intimacy. People touch other people and play with them. It's all quite ridiculous."

Reith chose his words with care. "This is probably normal human conduct-like becoming hungry, or something of the sort. You've never been 'boisterous'?"

"Of course not!"

"You've never even thought about it?"

"One can't help thinking."