However, the mere suspicion that any other man might be near by was enough to make the boys proceed with the greatest caution. Veiled by the fog,—which had been caused by the warm shower falling on the lake during the night,—they could be seen only by someone very near at hand, but there were other ways in which they might be betrayed. The sound of their voices or movements, the smell of the smoke from their cooking fire might reveal their presence. The secret nature of their quest made them anxious that their visit to the island should not become known. So they lighted no fire, breakfasting on the cold remains of last night’s corn porridge sprinkled with maple sugar. They talked little and in whispers, and took care to make the least possible noise.
Having decided to give at least one more day to the search for the furs, the lads climbed the steep slope and made their way to the head of the fissure. Up there the fog was much less thick than down in the cove. The crack in the rock had narrowed to a mere slit almost choked with tree roots upon which fallen leaves and litter had lodged. Near the edge, in a depression where there was a little soil, stood a clump of birch sprouts growing up about the stump of an old broken tree. In their search for some blaze or mark that might guide them, the two thought they had examined every tree in the vicinity.
That morning, as he was about to pass the clump of birches, Hugh happened to notice what a rapid growth the sprouts had made that season. The sight of the new growth suggested something to him. He began to pull apart and bend back the little trees to get a better view of the old stump. There, concealed by the young growth, was the mark he sought. A piece of the ragged, gray, lichen-scarred bark had been sliced away, and on the bare, crumbly wood had been cut a transverse groove with an arrow point.
Hugh promptly summoned Blaise. The cut in the old stump seemed to prove that the furs might not, after all, have been stolen from the hole in the rocks. The arrow pointed directly along the overgrown crack, which the lads traced for fifty or sixty feet farther, when it came abruptly to an end. They had come to a hollow or gully. The crack showed distinctly in the steep rock wall, but the bottom of the hollow and the opposite gradual slope were deep with soil and thick with growth. The rift, which widened at the outer end into a cleft, ran, it was apparent, clear through the rock ridge that formed the shore cliff. The searchers had now reached the lower ground behind that ridge. Which way should they turn next?
That question was answered promptly. The abrupt face of the rock wall was well overgrown with green moss and green-gray lichens. In one place the short, thick growth had been scratched away to expose a strip of the gray stone about an inch wide and six or seven inches long. The clean-cut appearance of the scratch seemed to prove that it had been made with a knife or some other sharp instrument. So slowly do moss and lichens spread on a rock surface that such a mark would remain clear and distinct for one season at least, probably for several years. There was no arrow point here, but the scratch was to the left of the crack. The boys turned unhesitatingly in that direction.
The growth in this low place was dense. They had to push their way among old, ragged birches and close standing balsams draped with gray beards of lichen which were sapping the trees’ life-blood. Everywhere, on the steep rock wall, on each tree trunk, they sought for another sign. For several hundred yards they found nothing, until they came to a cross gully running back towards the lake. In the very entrance stood a small, broken birch. The slender stem was not completely severed, the top of the tree resting on the ground.
“There is our sign,” said Blaise as soon as he caught sight of the birch.
“It is only a broken tree,” Hugh protested. “I see nothing to show that it is a sign.”
“But I see something,” Blaise answered promptly. “First, there is the position, right here where we need guidance. The tree has been broken so that it points down that ravine. The break is not old, not weathered enough to have happened before last winter. Yet it happened before the leaves came out. They were still in the bud. It was in late winter or early spring that tree was broken.”
“Just about the time father must have been on the island,” Hugh commented.