"Come on," said the doctor uneasily. "It's getting cold."
Next second they stopped short, nerves on edge, at a strange exclamation from Van Emmon. They looked around to see him pointing his light directly at the floor. Even in that unnatural suit of mail, his attitude was one of horror.
"Look here," he said in a low, strained voice. They went to his side, and instinctively glanced behind them before looking at what lay in the dust.
It was the imprint of an enormous human foot.
The first thing that greeted the ears of the explorers upon taking off their suits in the sky-car, was the exultant voice of Smith. He was too excited to notice anything out of the way in their manner; he was almost dancing in front of his bench, where the unknown machine, now reconstructed, stood belted to a small electric-motor.
"It runs!" he was shouting. "You got here just in time!" He began to fumble with a switch.
"What of it?" remarked the doctor in the bland tone which he kept for occasions when Smith needed calming. "What will it do if it does run?"
The engineer looked blank. "Why—" Then he remembered, and picked up one of the reels at random. "There's a clamp here just the right size to hold one of these," he explained, fitting the ribbon into place and threading its free end into a loop on a spool which looked as though made for it. But his excitement had passed; he now cautiously set a small anvil between himself and the apparatus, and then, with the aid of a long stick, he threw on the current.
For a moment nothing happened, save the hum of the motor. Then a strange, leafy rustling sounded from the mechanism, and next, without any warning, a high-pitched voice, nasal and plaintive but distinctly human, spoke from the big metal disk.