“Well, I can,” Brion told him. “They would leave their home if they took something with them of greater value. The bombs. If the bombs were hidden here, they might move them after the attack.” Sudden fear hit him. “Or they might move them because it is time to take them—to the launcher! Let’s get out of here, the quickest way we can.”

“I smell air from outside,” Ulv said, “coming from down there. This cannot be, because the magter have no entrances this low in their towers.”

“We blasted one in earlier—that could be it. Can you find it?”

Moonlight shone ahead as they turned an angle of the corridor, and stars were visible through the gaping opening in the wall.

“It looks bigger than it was,” Brion said, “as if the magter had enlarged it.” He looked through and saw the tracks on the sand outside. “As if they had enlarged it to bring something bulky up from below—and carried it away in whatever made those tracks!”

Using the opening themselves, they ran back to the sand car. Brion ground it fiercely around and turned the headlights on the tracks. There were the marks of a sand car’s treads, half obscured by thin, unmarked wheel tracks. He turned off the lights and forced himself to move slowly and to do an accurate job. A quick glimpse at his watch showed him there were four hours left to go. The moonlight was bright enough to illuminate the tracks. Driving with one hand, he turned on the radio transmitter, already set for Krafft’s wave length.

When the operator acknowledged his signal Brion reported what they had discovered and his conclusions. “Get that message to Commander Krafft now. I can’t wait to talk to him—I’m following the tracks.” He killed the transmission and stamped on the accelerator. The sand car churned and bounced down the track.

“They are going to the mountains,” Ulv said some time later, as the tracks still pointed straight ahead. “There are caves there and many magter have been seen near them; that is what I have heard.”

The guess was correct. Before nine o’clock the ground humped into a range of foothills, and the darker masses of mountains could be seen behind them, rising up to obscure the stars.

“Stop the car here,” Ulv said, “The caves begin not too far ahead. There may be magter watching or listening, so we must go quietly.”

Brion followed the deep-cut grooves, carrying the radio. Ulv came and went on both sides, silently as a shadow, scouting for hidden watchers. As far as he could discover there were none.