Rodman may not have been a Boy Scout, but he constructed this problem and its answer with a deft brain. Miss Seeby had asked for a specimen of the fragrant fern, which grew on the sides of cliffs. Specs had been sent away from school in disgrace, accompanied by Felix. He had not returned. The only cliffs near Lakeville were to the west, along the shore of the lake. Felix had smelled Specs' cap and run in that direction. It followed, as surely as two plus two make four, that he was endeavoring to lead somebody to the missing boy.
"Maybe poor Specs fell over a precipice and hurt himself," Rodman said, shivering uneasily. "All right, Felix, I'm coming. The old mass meeting can go hang!"
At first, while the dog kept to the road, there was nothing that Rodman could do save follow. But later, when Felix left the main highway where it curved to avoid the sandstone cliffs near the lake, and began pushing his eager nose through the underbrush and over tangles of grass, the boy recognized that this was virgin country. Specs could not have come that way without unconsciously leaving signs for anybody who came afterward.
Where some less observant boy might have found nothing, Rodman readily picked up the trail. A pebble, lying with its damp side up, proved that a careless foot had turned it over. A splatter of partially dried mud on the trunk of a tree revealed that the passer-by had left the spot some hours before. Broken branches, their tips toward the lake, pointed the way like arrows. Grass and leaves added their mute evidence by lying brushed forward till their under sides showed. It was comforting, at least, to be certain Specs had hiked over this very stretch.
"Yes, he came this way," Rodman told Felix. "Find him, old fellow!"
At the top of the wooded rise they had been ascending, the hill culminated in barren knobs, which broke off abruptly in sandstone cliffs, sheer to the lapping water of the lake. In places, the rock was solid, save for little dirt-filled crevices, from which hardy vegetation sprouted; in others, the stone had crumpled into fine sand, which day by day sifted downward till a niche had been formed in the solid wall. It was toward the top of one of these indentations that Felix raced, with Rodman hard on his heels.
Throwing himself flat on his stomach, the boy wriggled to the edge and peered down. Some twelve or fifteen feet below him, squatting on a narrow patch of sand, Specs McGrew was engaged in disconsolately tossing pebbles upon the placid bosom of the lake. On either side of his little prison, the walls of the precipice fell straight to the water's edge, apparently extending for hundreds of yards in both directions. Specs was safe enough, to be sure, but he was as effectually cooped upon the tiny plot of sand by the smooth rock cliffs and the deep lake as if the iron bars of a cage encompassed him.
"Hello, Specs!"
The imprisoned boy looked up. "Oh, it's you," he said sullenly. "Got a rope?"