Presently he heard a heavy knocking above his head and, guessing the cause, shrank back for shelter into the mouth of a small cave adjoining. A moment later a man emerged from one of the other chambers and approached the lift. Dick was curious to see how it worked. There was, as he could see, a small electric motor fitted to it, but where could the necessary power come from?
The new-comer carried in his hand a tiny machine which was in every respect a duplicate in miniature of the big one on the central table. But it was so small that the man carried it easily in one hand. From it ran a pair of electric cables which the man proceeded to connect with the terminals of the motor.
Placing the machine on the ground he gave the wheel a sharp turn. Immediately the tiny machine began to revolve, throwing out flashes and flames exactly like the larger one but on a miniature scale.
Clearly, however, there was considerable power in it, for the lift at once commenced to descend. On it stood a man whom Dick instantly recognised as Gronvold. And he was accompanied by the sailor whom Dick had left safely tied up in their camp. Evidently Gronvold had found and released him.
Their position was now indeed one of terrible gravity.
As soon as the lift reached the bottom the two men stepped off and the lift reascended, moving upward with an ease which showed the tremendous power developed by the tiny machine. Here, indeed, was something of which Dick had had no previous experience.
The three men crossed the cave to the shelter occupied by the man who worked the big machine, who was evidently the captain, and Dick knew there was no time to be lost.
Directly the men entered the shelter, Dick dashed across the cave to join the others, snatching out his revolver as he ran.
He had nearly reached them, when a whistle blew and instantly half a dozen men rushed from different caves. They were discovered!
“Take care of Yvette, Jules!” Dick yelled as, with Scott at his side, he faced round to the men who were rushing at them from three sides.