"Should have thought of this before," he growled. "In war they carried maps—Martians and Xians alike. Now let's see. What looks important on the dark hemisphere? Something that a guy like Fane would go for. If that's the way it is...."

The three men huddled together, squinting at the stiffened parchment in the dim light of the solar corona. Dark lines showed highways passing between jagged markings that must be mountain ranges. Rick coordinated what he knew of Mercury from astronomical photographs taken at the great observatory on the moon, with what he saw on the map, and thus found out where he and his companions were.

His attention was drawn inevitably to a great golden circle on the parchment. All roads led to it.

"No matter how you stack it, that must be the place we want to reach," Rick said. "But it's four thousand miles away."

"I see there's a tunnel, too," Lattimer joined in. "That heavy red line. I know Martian maps. It's for a kind of jet-train. Am I cockeyed to think that some cars might still work?... If we could get to a tunnel entrance. But it's fifty miles at the nearest. Some walk!"

"We're stranded in a white hell, with a good chance of being knocked off before we die from more natural causes," Finden said. "So we've got to think boldly. How about finding something like what Fane seemed to be using? Then we could rocket to that golden circle place."

"Yeah—'finding'," Rick retorted. "Then there's the question of our being able to fly it in a hurry. Uh-uh—the tunnel's a long shot, too, but a better bet. If we can locate a large, flat sheet of metal, we can bend up one end for a prow and use our blasters for reaction-propulsion to improvise a toboggan that will ski over the frozen air and frost."

They crept further along the ditch to get away from the deadly little ovoids that must still lurk near. Then they arose and ran. There was a dazzling blast from behind them, and they ran faster, maybe a mile or more, stumbling through deep drifts of white.

They came to more Xian wreckage. Hurriedly they searched, as some vague bulk prowled, far off to their left. But at last they found and shaped what they wanted. They crouched on the sheet of metal, and fired continuous streams of protons rearward. Soon their arms, braced against the thrust of incandescent fire, ached furiously.

The weapons were hot in their hands. But under the rocket-like kick of the blasters they made speed even though their makeshift toboggan, unguided by runners, careened crazily. The hour it took to cover fifty miles seemed an age.