He tried once more to rise, but he couldn't feel his limbs.

"It's a tree stump!" Poole snapped excitedly into the radio link. "Don't you see, the toolmakers are the tree stumps! Bill, look at the pictures, damn it. They are different phases of a single life cycle: an active intelligent phase, followed by a loss of mobility."

"Maybe," Dzik said. "But we didn't find anything like a nervous system in that tree stump we opened up."

"So their brains, their nervous systems, are absorbed. When they're no longer needed." A memory came to Poole. "The juvenile sea-squirt. Of course."

"The what?"

"It's an exact analogy. The sea-squirt seeks the rock to which it's going to cling, for the rest of its life. Then, its function fulfilled, its brain dissolves back into its body..."

Dzik sounded doubtful. "But these were toolmakers."

"Yeah." Poole peered up at the empty sky. "But what use is intelligence, on a world like this? No raw materials. Nowhere to get to. An unchanging sky, inaccessible... Bill, they must have abandoned their toolmaking phase ages ago. Now they use their intelligence solely to find the best place to lie in the Sun. The shadows of hills; the places with the highest temperature differentials. Perhaps they compete. Then their awareness dissolves--"

But the stationary, kneeling titan before him, drawn by the flitter, had come to rest on a plain, he realized now. No shade; useless. It would die, never reaching the tree stump stage.

"Mike." Dzik's voice crackled. "You're right, we think. We're looking over some of our photos again. There's a whole herd of the damn things, on the far side of the worldlet from our beachhead."

Poole rested his hands on the controls. This would take care -- a delicacy of touch he wasn't sure he had. He applied a single, brief impulse to the jets. The flitter sailed smoothly into the sky.

Dzik was still talking. "The superfluid helium must be crucial to the animal phase. Superfluid gives you a huge mechanical advantage; in microgravity helium pumps could exploit tiny temperature differences to move bulky masses of ice." He laughed. "Hey, I guess we don't need to worry about funds for the future. The whole System is going to beat a path to our door to see this -- as long as we can work out a way to protect the ecology..."

"Right." Using verniers Poole took the flitter through slow curves around the fallen toolmaker; with brief spurts of his main motor he raised wakes in the ice, sculpting them carefully. "And if we can't, we'll implode the damn wormhole. We'll get funds for the Cauchy some other way."

The argument went on for some time.

It took Poole five or six sweeps before he was satisfied with the hill he'd built.

Then, still careful, he lifted away from Alaska for the last time.

The Sun dipped, as the world turned. A shadow fell across Sculptor. Blood pulsed through him. With renewed energy his roots snuggled into the ground.