"The head of Spiro," thought Miles and Ward with sinking hearts.

They had fallen into the power of the leader of the insurgent workers!

Spiro — for it was indeed he — regarded them with pitiless eyes. His English was slower and not as fluent as that of Zoro, and his words harder to understand.

"You Americans, beings of another world, have come here at the bidding of the Heads to slay and kill for gold."

He paused. "I who for three years studied your country, learned its language, history, did not believe men of your race could be so vile."

He paused again, and Ward broke out hotly, "It is true that we came here to fight for gold, but who are you to speak of vileness? Have you not turned on the Heads, your benefactors, now your brothers, who raised you to their height? Are you not leading a revolt of the workers which would deny them the means of sustaining life? Are you not seeking to perpetrate — murder?"

Spiro regarded him slowly. "Is it possible you are in ignorance of what those means are? Listen, then, while I tell you the hideous truth. Since the dawn of our history, until the present moment, the Heads have maintained their lives by draining blood from the veins of thousands of Apexans yearly!"

The Americans' faces whitened. "What do you mean?" breathed Ward.

"I mean that the artificial blood pumped by mechanical hearts through the brains of the Heads — yes, and that is now being pumped through my own!" cried Spiro bitterly—"is manufactured from human blood. Human blood is the basis of it. And to get that blood every Apexan must yield his quota in the temple. Slowly but surely this practice is sapping the vitality of the race. But though the Apexans realized this they were afraid to speak against the custom. For the Heads were worshipped as gods; and when the gods spoke, blasphemers died — horribly."

M iles and Ward shuddered.