"They won't pass a Scout from Earth?"

"Put it this way. The badges you need add up to one thing, Mooncraft. The examiners are old Moon hands; you won't get by with book answers. They'll know how long you've been here and they'll know you don't know enough."

Bruce thought about it. "It's not fair!"

Sam snorted. "Mooncraft isn't a game; it's the real thing. 'Did you stay alive?' If you make a mistake, you flunk - and they bury you."

Bruce had no answer.

Presently they came to hills; Sam stopped and called Base Camp. "Parsons and Hollifield, Troop One - please take a bearing."

Shortly Base replied, "One one eight. What's your mark?"

"Cairn with a note."

"Roger."

Sam piled up stones, then wrote date, time, and their names on paper torn from a pad in his pouch, and laid it on top. "Now we start up."

The way was rough and unpredictable; this canyon had never been a watercourse. Several times Sam stretched a line before he would let Bruce follow. At intervals he blazed the rock with his hammer. They came to an impasse, five hundred feet of rock, the first hundred of which was vertical and smooth.

Bruce stared. "We're going up that?"

"Sure. Watch your Uncle Samuel." A pillar thrust up above the vertical pitch. Sam clipped two lines together and began casting the bight up toward it. Twice he missed and the line floated down. At last it went over.

Sam drove a piton into the wall, off to one side, clipped a snap ring to it, and snapped on the line. He had Bruce join him in a straight pull on the free end to test the piton. Bruce then anchored to the snap ring with a rope strap; Sam started to climb.

Thirty feet up, he made fast to the line with his legs and drove another piton; to this he fastened a safety line. Twice more he did this. He reached the pillar and called, "Off belay!"

Bruce unlinked the line; it snaked up the cliff. Presently Sam shouted, "On belay!"

Bruce answered, "Testing," and tried unsuccessfully to jerk down the line Sam had lowered.

"Climb," ordered Sam.

"Climbing." One - sixth gravity, Bruce decided, was a mountaineer's heaven. He paused on the way up only to unsnap the safety line.

Bruce wanted to "leapfrog" up the remaining pitches, but Sam insisted on leading. Bruce was soon glad of it; he found three mighty differences between climbing on Earth and climbing here; the first was low gravity, but the others were disadvantages: balance climbing was awkward in a suit, and chimney climbing, or any involving knees and shoulders, was clumsy and carried danger of tearing the suit.

They came out on raw, wild upland surrounded by pinnacles, bright against black sky. "Where to?" asked Bruce.

Sam studied the stars, then pointed southeast. "The photomaps show open country that way."

"Suits me." They trudged away; the country was too rugged to lope. They had been traveling a long time, it seemed to Bruce, when they came out on a higher place from which Earth could be seen. "What time is it?" he asked.

"Almost seventeen," Sam answered, glancing up.

"We're supposed to be back by midnight."

"Well," admitted Sam, "I expected to reach open country before now."

"We're lost?"

"Certainly not! I've blazed it. But I've never been here before. I doubt if anyone has."

"Suppose we keep on for half an hour, then turn back?"

"Fair enough." They continued for at least that; Sam conceded that it was time to turn.

"Let's try that next rise," urged Bruce.

"Okay." Sam reached the top first. "Hey, Bruce - we made it!"

Bruce joined him. "Golly!" Two thousand feet below stretched a dead lunar plain. Mountains rimmed it except to the south. Five miles away two small craters formed a figure eight.

"I know where we are," Sam announced. "That pair shows up on the photos. We slide down here, circle south about twenty miles, and back to Base. A cinch - how's your air?"

Bruce's bottle showed fair pressure; Sam's was down, he having done more work. They changed both bottles and got ready. Sam drove a piton, snapped on a ring, fastened a line to his belt and passed it through the ring. The end of the line he passed between his legs, around a thigh and across his chest, over his shoulder and to his other hand, forming a rappel seat. He began to "walk" down the cliff, feeding slack as needed.

He reached a shoulder below Bruce. "Off rappel!" he called, and recovered his line by pulling it through the ring.

Bruce rigged a rappel seat and joined him. The pitches became steeper; thereafter Sam sent Bruce down first, while anchoring him above. They came to a last high sheer drop. Bruce peered over. "Looks like here we roost."

"Maybe." Sam bent all four lines together and measured it. Ten feet of line reached the rubble at the base.

Bruce said, "It'll reach, but we have to leave the lines behind us."

Sam scowled. "Glass lines cost money; they're from Earth."

"Beats staying here."

Sam searched the cliff face, then drove a piton. "I'll lower you. When you're halfway, drive two pitons and hang the strap from one. That'll give me a changeover."

"I'm against it," protested Bruce.

"If we lost our lines," Sam argued, "we'll never hear the last of it. Go ahead."

"I still don't like it."

"Who's in charge?"

Bruce shrugged, snapped on the line and started down.

Sam stopped him presently. "Halfway. Pick me a nest."

Bruce walked the face to the right, but found only smooth wall. He worked back and located a crack. "Here's a crack," he reported, "but just one. I shouldn't drive two pitons in one crack."

"Spread 'em apart," Sam directed. "It's good rock." Reluctantly, Bruce complied. The spikes went in easily but he wished he could hear the firm ring that meant a piton was biting properly. Finished, he hung the strap. "Lower away!"

In a couple of minutes he was down and unsnapped the line. "Off belay!" He hurried down the loose rock at the base. When he reached the edge of it he called, "Sam! This plain is soft stuff."

"Okay," Sam acknowledged. "Stand clear." Bruce moved along the cliff about fifty feet and stopped to bind on skis. Then he shuffled out onto the plain, kick turned, and looked back. Sam had reached the pitons. He hung, one foot in the strap, the bight in his elbow, and recovered his line. He passed his line through the second piton ring, settled in rappel, and hooked the strap from piton to piton as an anchor. He started down.

Halfway down the remaining two hundred feet he stopped. "What's the matter?" called Bruce.

"It's reached a shackle," said Sam, "and the pesky thing won't feed through the ring. I'll free it." He raised himself a foot, then suddenly let what he had gained slip through the ring above.

To Bruce's amazement Sam leaned out at an impossible angle. He heard Sam cry "Rock!" before he understood what had happened - the piton had failed.

Sam fell about four feet, then the other piton, connected by the strap, stopped him. He caught himself, feet spread. But the warning cry had not been pointless; Bruce saw a rock settling straight for Sam's helmet. Bruce repeated the shout.

Sam looked up, then jumped straight out from the cliff. The rock passed between him and the wall; Bruce could not tell if it had struck him. Sam swung in, his feet caught the cliff - and again he leaned out crazily. The second piton had let go.

Sam again shouted, "Rock!" even as he kicked himself away from the cliff.

Bruce watched him, turning slowly over and over and gathering momentum. It seemed to take Sam forever to fall.

Then he struck.

Bruce fouled his skis and had to pick himself up. He forced himself to be careful and glided toward the spot.

Sam's frantic shove had saved him from crashing his helmet into rock. He lay buried in the loose debris, one leg sticking up ridiculously. Bruce felt an hysterical desire to laugh.