Gibesh, who had been standing guard duty, came to Tirin and Shevek after dinner, looking uneasy. “I thought I heard Kad saying something in there. In a sort of funny voice.”

There was a pause. “We’ll let him out,” Shevek said. Tirin turned on him. “Come on, Shev, don’t go mushy on us. Don’t get altruistic! Let him finish it out and respect himself at the end of it.”

“Altruistic, hell. I want to respect myself,” Shevek said, and set off for the learning center. Tirin knew him; he wasted no more time arguing with him, but followed. The eleven-year-olds trailed along behind. They crawled under the building to the cell. Shevek knocked one wedge free, Tirin the other. The door of the prison fell outward with a flat thump.

Kadagv was lying on the ground, curled up on his side. He sat up, then got up very slowly and came out. He stooped more than necessary under the low roof, and blinked a lot in the light of the lantern, but looked no different from usual. The smell that came out with him was unbelievable. He had suffered, from whatever cause, from diarrhea. There was a mess in the cell, and smears of yellow fecal stuff on his shirt. When he saw this in the lantern light he made an effort to hide it with his hand. Nobody said anything much.

When they had crawled out from under the building and were heading around to the dormitory, Kadagv asked, “How long was it?”

“About thirty hours, counting the first four.”

“Pretty long,” Kadagv said without conviction.

After getting him to the baths to clean up, Shevek went off at a run to the latrine. There he leaned over a bowl and vomited. The spasms did not leave him for a quarter of an hour. He was shaky and exhausted when they passed. He went to the dormitory common room, read some physics, and went to bed early. None of the five boys ever went back to the prison under the learning center. None of them ever mentioned the episode, except Gibesh, who boasted about it once to some older boys and girls; but they did not understand, and he dropped the subject.

• • •

The Moon stood high over the Northsetting Regional Institute of the Noble and Material Sciences. Four boys of fifteen or sixteen sat on a hilltop between patches of scratchy ground-holum and looked down at the Regional Institute and up at the Moon.

“Peculiar,” said Tirin. “I never thought before…

Comments from the other three on the self-evidence of this remark.

“I never thought before,” said Tirin unruffled, “of the fact that there are people sitting on a hill, up there, on Urras, looking at Anarres, at us, and saying, ‘Look, there’s the Moon.’ Our earth is their Moon; our Moon is their earth.”

“Where, then, is Truth?” declaimed Bedap, and yawned.

“In the hill one happens to be sitting on,” said Tirin.

They all went on staring up at the brilliant, blurry turquoise, which was not quite round, a day past its full. The northern ice cap was dazzling. “It’s clear in the north,” Shevek said. “Sunny. That’s A-Io, that brownish bulge there.”