"None," replied Zoro. "I know there are no other tah-a-las inside these rooms, since it is the nature of these beasts to rush to each other's aid when they scream. And as for outside attacks, the laboratories are insulated against any the insurgent workers can make. Their weapons are poor--the green men use but clubs. No, it is not their attacks we fear but their refusal to furnish us with supplies. They worshipped us as gods, and the giving of supplies was long a religious rite. But now they doubt our divinity, and, since they no longer listen to or obey our decrees, we have no means of punishing them. Spiro is responsible for this." "Spiro?" questioned the two men. "He whom we raised to the dignity of godhead on the accidental death of Bah-koo, causing a deep sleep to fall upon him in the temple and grafting his head upon the mechanical body left by the latter. Twice before we had done this with citizens of Apex, and how were we to know that Spiro would resent it? True, he was in love with Ah-eeda, but the physical passions of men die with the organisms that give them birth. For three years he dwelt with us in the laboratories, learning the wisdom of the Heads, and then,"--Zoro's face became forbidding--"he denounced us to the people. Though there was more or less discontent, they would never have dared defy us save for him. He told them that our curses could do no harm, that we were merely the heads of men like himself and would die if they refused to give us the wherewithal to renew blood. * * * * * "But this refusal of theirs is an evil thing," he cried, looking at the Americans with his strangely colored eyes. "It violates the custom of ages, and strikes at the very roots of our existence. So we held council and sent two of our number to Earth after men and weapons to enforce our demands. For years we had watched Earth, seen its myriad civilizations rise and fall, studied the coming of America to power and importance. So it was to America that Solino went, by way of the tunnel that still exists under the Atlantic--" "And hired us," interrupted Ward, "and brought us to the tunnel in the submarine-car where we--" "Stepped into the crystal chamber," finished Zoro. "That chamber is a re-vibrating device of certain rays and chemicals. The shutting of the door closed the switches and hurled your bodies to where a receiving-station on this plane integrated them again." So they were not at the bottom of the ocean. They were--stupendous thought--living in a new world of matter! "Spiro suspected our plans," continued Zoro. "He isolated us in our laboratories, and, by means of a crystal tube, went through to the tunnel, tore up a section of track, and wrecked the submarine-car. But his act was only partially successful. You two escaped death; you are here; you are ready to keep faith and fight in our service."