But that night Shann dreamed. No climbing of a skull-shaped mountain this time. Instead, he was again on the beach, laboring under an overwhelming compulsion, building something for an alien purpose he could not understand. And he worked as hopelessly as a beaten slave, knowing that what he made was to his own undoing. Yet he could not halt the making, because just beyond the limit of his vision there stood a dominant will which held him in bondage. And he awoke on the beach in the very early dawn, not knowing how he had come there. His body was bathed in sweat, as it had been during his day's labors under the sun, and his muscles ached with fatigue. But when he saw what lay at his feet he cringed. The framework of the outrigger, close to completion the night before, was dismantled--smashed. All those strips of hide he had so laboriously culled were cut--into inch-long bits which could be of no service. Shann whirled, ran to the shell he had the night before pulled from the water and stowed in safety. Its rounded dome was dulled where it had been battered, but there was no break in the surface. He ran his hands anxiously over the curve to make sure. Then, very slowly, he came back to the mess of broken wood and snipped hide. And he was sure, only too sure, of one thing. He, himself, had wrought that destruction. In his dream he had built to satisfy the whim of an enemy; in reality he had destroyed; and that was also, he believed, to satisfy an enemy. The dream was a part of it. But who or what could set a man dreaming and so take over his body, make him in fact betray himself? But then, what had made Thorvald maroon him here? For the first time, Shann guessed a new, if wild, explanation for the officer's desertion. Dreams--and the disk which had worked so strangely on Thorvald. Suppose everything the other had surmised was the truth! Then that disk _had_ been found on this very island, and here somewhere must lie a clue to the riddle. Shann licked his lips. Suppose that Thorvald had been sent away under just such a strong compulsion as the one which had ruled Shann last night? Why was he left behind if the other had been moved away to protect some secret? Was it that Shann himself was wanted here, wanted so much that when he at last found a means of escape he was set to destroy it? That act might have been forced upon him for two reasons: to keep him here, and to impress upon him how powerless he was. Powerless! A flicker of stubborn will stirred to respond to that implied challenge. All right, the mysterious _they_ had made him do this. But they had underrated him by letting him learn, almost contemptuously, of their presence by that revelation. So warned, he was in a manner armed; he could prepare to fight back.