Early the next morning they paddled up the river to the point where Mac's blazed trail came down to the shore, and set out to reconnoiter the den. After half an hour's tramping across the woods they reached the rocky ridge; through the field-glass they scrutinized the lair, which was about two hundred yards away.
Not a hair of a fox was in sight, but the burrow looked as if it could be opened with spade and pick. Horace thought they ought to do that first of all; in that way they could capture the cubs before there was any possible danger of the old foxes' moving the den.
On their way back to camp, Mac stopped at a marshy pool and cut a great armful of willow withes.
"It's lucky that I once used to watch an old willow worker making baskets and chairs," he said. "I'll see if I've forgotten the trick of it. We've got to make a cage, for we'll need one the instant we capture one of those cubs."
He made a strong framework of birch, with bars as thick as his wrist, which he notched together, and lashed with deer-hide. Then he had the framework of a box about three feet long, two feet wide, and two feet deep, through which he now began to weave the tough, pliable withes.
He did not altogether remember the trick of it, and he had to stop frequently to plan it out. He worked all that afternoon, and continued his labor by firelight. He did not finish the cage until the middle of the next forenoon. It was rough-looking, but light, and nearly as strong as an iron trunk, and had a door in the top.
All that remained for them to do now was to catch the game. They ate a hasty luncheon, and carrying the cage, the trap, the axe, the spade and pick, two blankets, and the guns, started back along Mac's blazed trail. So great was their eager hurry that they stumbled over roots and stones.
Clambering down the ravine, they cautiously approached the foxes' den. The opening to the burrow was a triangular hole between two flat rocks. From it came a faint odor of putrid flesh. The ground in front was strewn with muskrat tails, small bones, and the beaks and feet of partridges and ducks. From the rocks Fred picked off two or three black hairs.
The boys looked into the dark hole and listened intently. They could not hear a sound, but they knew that the cubs, at any rate, must be within. Mac cut a sapling, trimmed it down and sharpened one end of it; with that as a lever the boys loosened the rocks at the entrance of the burrow, and rolled them aside. The burrow ran backward and downward into the ground, but there seemed to be nothing in their way now except earth, gravel, and roots. Horace picked up the spade and began to dig; occasionally he had to stop to cut a tree root or pick out a rock. Meanwhile, Peter and Fred stood close behind him, ready to stuff the blankets into the hole in case the occupants should try to bolt.
They uncovered the burrow for about four feet; then they had to dislodge another rather large stone. There seemed to be a large, dark cavity down behind it. When they stopped to listen, they could hear a slight sound of movement in the darkness, and a faint squeaking.