"Somehow, I don't think Altorius would do such a thing," he said at last. "Let's think back and see if we can't piece this treachery together."

"Wish I had your faith in the Emperor—but I haven't." Alden's handsome face twisted itself into a wry smile.

"Let's see, now," persisted Nelson, fingering a square jaw upon which sprouted a thick growth of reddish bristles. "There was a deputation of priests to see Altorius yesterday. They were clamoring for the return of Altara—the Sacred Virgin—and looked pretty mad when he put them off."

"Maybe this is the private doing of the priests," admitted Alden. "Anyway, we're in one devil of a fix. There's certainly no way out of this calaboose—and those damned brutes out there look hungry."

Nelson frowned, deep in thought. "Wish I could find a reasonable explanation. I really don't think it's Altorius; still, that's what you get for mixing in on the politics of these forgotten kingdoms."

"But," reminded the other, "you had no choice, old lad. Remember, you mixed in to save me."

From across the courtyard rang a loud, penetrating shriek of fear that made the two aviators spring to their feet and rush to the bars. Peering across the court, they discovered three naked men shrieking and clinging frantically to the bars of an exactly similar cell.

"What's wrong with them?" demanded Alden as the agonized screams rang louder still.

"I don't know," was Alden's breathless reply. "But what's that noise?"

A curious metallic clanking sound filled the poisoned air, and for a moment Nelson remained utterly puzzled. Then, as the noise grew louder, the allosauri commenced to betray a strange restlessness. They ceased basking and feeding, and their hideous heads commenced to dart quickly this way and that.