As though answering an unheard vibration, a door opened and they lumbered in. The door closed behind them. For a moment they were in such darkness that even the beam from the tractor seemed alien. Then another door started to open before them and a widening shaft of light was there to greet them.

Odin was thinking that each race must have some craft at which it excels all others. If so, then the building of air-locks was certainly the Brons’ highest art.

Then they advanced into a cavern where five tiny atomic suns were strung out at equal distances upon the ceiling. The cavern was geometrical. Roughly, it was a mile long, half a mile wide, and half a mile high. The floor was smooth; the walls were sheer. “As though they had been shaped by human hand,” Odin thought, but he soon learned that other hands had sheered those walls.

In the very middle of the cavern was a little lake, shaped in the same proportion as the floor. It was surrounded by green grass, and at one corner was a profusion of water-lilies and cat-tails. There were no trees, but flowers were everywhere. A few small bushes. Here and there were great clumps of vines. Odin guessed them to be wild cucumber and trumpet vines, for they had grown riotously.

It was beautiful indeed, but there were other things to catch the eye. At least a hundred hemispheres—little igloos of porcelain—were scattered about the floor of the cave. Each one was a different color. They shimmered and glittered. Scarlet, mauve, mother-of-pearl, the blue Capri, and the blue of cobalt. Pinks, yellows, oranges. Every possible shade had gone into those porcelain igloos. And the lighted walls of the cavern were covered from floor to ceiling with numberless figures, marching, fighting, working, playing. At first, Odin thought it was a vast procession of armored knights with huge chests and closed visors. But none of them stood completely erect—and each of them had two sets of arms.

Straining his eyes at the windows to look up, Odin learned that the vast ceiling was completely covered by similar figures.

In contrast to these was one huge tower of rough stone which Odin guessed to be new.

So they came to the moon, and disembarked. And at last Odin felt the lightened pull of the moon’s gravity. He felt so free that he laughed and leaped into the air and turned a somersault just as he had dreamed of doing. Then one of the Brons’ scientists gave him a heavy pair of shoes—as if to remind him that no man can be altogether free.

As he glumly strapped the heavy shoes to his feet, Jack thought of something his father had told him: “No man was ever really free, unless it was Robinson Crusoe. Then Friday showed up and became Crusoe’s servant, and Crusoe’s freedom flew away.”