"Because," replied Andy, "I am afraid our life-torches won't last much longer. Mine seems to be weakening. I have to hold it very close to my face now to breathe in comfort, while at first the oxygen from it was so strong that I could hold it two feet off and never notice the poisonous moon vapors."
This was a new danger, and, thinking of it, the faces of the boys became graver than ever. Death seemed bound to get them somehow.
Two more days went by. They had now been lost on the moon over a week. Each one now noticed that his life-torch was weakening. How much longer would they last? They dared not answer that question. They could only hope.
The sun, too, was moving away from them. Soon the long night would set in. By Mark's computation there was only three more days of daylight left. What would happen in the desolate darkness?
As they were returning from the black pool, with their water bottles filled, and put inside the fur bags to prevent the frost from reaching them, Mark happened to gaze over across a line of towering peaks. What he saw caused him to gasp in astonishment.
"Jack! Andy! See!" he whispered hoarsely, pointing a trembling finger at the sky.
There, outlined against the cloudless heavens, was a long, black shape, floating through the air about two miles distant.
"The projectile! The Annihilator!" yelled Jack. "Shout! Call to them! Wave your hands! Andy, fire your gun! They have started off, and they can't see us. We must make them hear!"
Together they raised their voices in a mighty shout. The old hunter fired his gun several times. They waved their hands frantically.
But the projectile never swerved from its course. On it moved slowly, those in it paying no heed to the wanderers, for they did not hear them. Andy fired his gun again, but the signal failed, and a few minutes later the Annihilator was lost to sight behind a great peak.