Scotty moved rapidly but silently, across the bottom of the cliff, taking advantage of every overhanging rock. When Scotty was perhaps ten yards away, Rick moved into action. He picked up a rock, hefted it, then threw it into the pile of cans. They scattered noisily, bringing a rifle shot in reply. Rick thought swiftly, then peeled off his shirt and wrapped it in a good-sized rock. He gauged the distance and heaved it in the direction opposite the one Scotty had taken, aiming for a niche under an overhang six yards away. He hoped the motion would be mistaken for one of them. Evidently he succeeded, because a rifle slug chipped rock a foot away from the shirt as it rolled under the overhang. Raising his head cautiously, he saw a rock perched precariously on the steep slopes. Evidently it had come to rest there, or the rains had washed away much of its support. He found a rock to throw, sighted with care, and tossed it underhand. It struck directly under the balanced rock and dug away enough dirt to upset its equilibrium. The rock tumbled down, bringing a tiny landslide of other rocks and dirt with it. There was no response from the rifle this time. Rick turned to see how Scotty was doing, but his pal was out of sight, behind some boulder along the way. Now what? His bag of tricks was almost exhausted. He looked outward, across the road. A few yards to the right of the campfire and cache of cans was a rock pile. It was big enough to shield him, if he could make it. He took a deep breath. If he dodged and twisted fast enough, the rifleman probably couldn't hit him, and he would certainly have the man's full attention. That would give Scotty a better chance. He chose a rock, hefted it, and got up into a sprinting position. He made sure of his footing, then simultaneously tossed the rock sideways to attract the rifleman's eye, and charged out of the niche. Ten feet and he jumped sideways, took two forward leaps, and went sideways again. The rifle barked and dirt spurted where he had just been. But by then Rick was within reach of the rock pile, and he went over it in a headlong dive, rolling like a tumbler as he landed. Quickly he flattened out, as close to the rocks as he could get. A bullet whined off the top of the pile, and then there was silence. Rick's heart pounded and his breath came in gasps. He had made it! But how about Scotty? He risked a push-up that brought his head to the level of the upper rocks in time to see Scotty fire his first sling stone. His pal had reached a position just below the top of the mesa, where his stones would clear the top without exposing him. As Rick watched, Scotty put another stone in the pouch and let fly. The stone smashed into rock on top of the mesa. A third stone, and Rick suddenly caught a glimpse of motion on the mesa top, directly above him. The rifleman was changing position! Evidently Scotty's stones were coming too close! "Watch it!" he yelled. "Watch out, Scotty! He's moving!"