By this time the other men had reached there. Conley was stammering, "Jim, we--we can't leave the supplies! The sleds!" "Sleds be damned!" Jim exclaimed in an ecstasy of excitement. "This is better than a hundred sleds! Do you want to find your radite or don't you? Are you going to M'Tonak or not!" Hesitantly, Conley entered the strange craft. The others glanced nervously, then quickly followed, as though not wishing to be left alone. "I--" Conley began doubtfully. That seemed to be a signal. Instantly a well-oiled metal door slid shut behind them. Motors began to purr gently beneath their feet. The car swung around in a great circle, and they were heading into the north. From one of the comfortable pneumatic seats Jim watched the white unending landscape flashing past. He felt strangely exhilarated now that he was on the very threshold of his quest; for that they were being taken to the long-hidden, legendary city of M'Tonak, he did not for a moment doubt. It had not yet occurred to him to wonder why they were being taken. But of one thing he was sure. He said, turning to Conley: "Why do you suppose they sent the car for us? It must be that they _know_ whenever anyone is approaching M'Tonak! Always! Other expeditions must have reached here in the same manner, else why were they never found by the men who came later?" Conley nodded soberly. "And that must mean that, once inside M'Tonak, men are unable to leave." IV It seemed minutes later, but it might have been hours, that Jim Landor sat up with a start, aware that the softly purring motors had lulled him to sleep. He wondered how long they had been travelling. Now their speed seemed to have diminished considerably. But something else seemed strange. He turned to the tiny window, and was startled to see no more Polar Cap, no more expanse of white ice. Instead they were in a strange dark place. It was several seconds before he could adjust his eyes sufficiently to see that a wall was very close. It seemed to be moving backward and slightly upward. He knew then that they were descending somewhere at about a thirty degree angle. "When did this begin?" he asked, turning to Conley. "About twenty minutes ago. We must be a mile below the ice by now." So M'Tonak lay somewhere _beneath_ the Polar Cap! That was why men in ages past had been unable to find it, until it became a legend on a par with Earth's lost Atlantis! Jim tensed in his seat now as he thought of all the conflicting reports he had heard about M'Tonak; vague questions crossed his mind to which there were only vaguer answers.