They saw what had caused the sudden stiffening of the Three. Sitsumi, busily engaged at something else nearby, quietly approached the Three. "What is it?" he asked. "Rescue planes," said Wang Li. "New York City sends six fliers to rescue Jeter and Eyer. New planes. They'll reach us, Sitsumi. We should have thought to destroy all dangerous air ports. A fatal oversight!" Sitsumi's eyes were grave. He looked at each of the Three in turn. "God!" said Jeter's whispering lips. "If we could read their minds! If only we could guess what it is they fear, we'd have the secret by which we might destroy them." "They're vulnerable," said Eyer, "but how?" "Watch!" said Jeter. "Listen! And here's to those six unknowns coming up to, maybe, get the same dose we're due for! We were closely watched. New York City knows exactly where we vanished in the sky. Those six planes are aiming at us--at a spot in the stratosphere they can't see. And yet, why should Sitsumi and the Three be so fearful? All they have to do is move a half mile in any direction and they'll never find them." "But to move will interfere with their plans," said Eyer. "Lucian, look at the expressions on their faces! Something tells me they are vulnerable in ways we haven't guessed at. If we knew the secret maybe we could destroy them. We've got to discover their weak spot." * * * * * There was a long pause while Jeter and Eyer watched the rescue ships come climbing up the endless stairways of the sky. Then Jeter whispered again, guardedly as usual. "There seems to be nothing we can do. If our friends are able, by some miracle, to do something, you know what that means to us?" "It means we're as good as dead no matter what happens," replied Eyer. "But we're only two--and there must be a million buried under the debris in New York City alone. If we can do anything at all...." There he left it. The partners looked at each other. Each read the right answer in the other's eyes. When the showdown came they'd die as cheerfully as they knew how, hoping to the last to do something for the people who must still hope that, somehow, they would cause this bitter cup of catastrophe to pass from them. And there were thousands upon thousands whose blood cried out for vengeance. The hours sped as the six planes fled upward. To the ears of the partners, through the audiphones, came the stern roaring of their motors. In their eyes they bulked larger and larger as the time fled away. The sand in the hour glass was running out. When it was all gone, and the time had come, what could the helpless Jeter and Eyer hope to accomplish? For an hour they studied the concerned faces of Sitsumi and the Three. They were fearful of something. What? CHAPTER XI _To the Rescue_