Raymond had succeeded in keeping them supplied with small game. The day before he had shot two fine grouse, and there was still some of that meat. The boys ate their cold supper and spread their beds before it became dark, then sat in the gloom talking. Night fell rapidly, and with the heavy downpour of rain it soon became very dark. The boys were just about to roll up in their blankets for the night when they heard strange noises outside. There was a low, muttered grumbling, mingled with a strange whimpering. The boys sat breathless, listening intently. At first they thought it must be some large animal, though they had seen no animals larger than rabbits. In a moment, however, the voice whimpered complainingly, and the boys thought it was surely a person in distress. The storm was turning colder, and the rain and sleet were coming down in such volumes that any one caught in it, perhaps insufficiently clothed, would suffer greatly. Raymond was about to step to the opening and call out that there was shelter near, when the whimpering ceased and the growling began again, in a heavier, gruffer tone than at first. It was plain that it could not be a human being that made such noises, and it seemed to the frightened boys that it must be a very large animal. “What can it be, Sid?” whispered Raymond. “I don’t know, unless it’s a wolf. We’ve read of the terrible Russian wolves.” “The animal that’s growling like that is bigger than a wolf,” declared Raymond. “Then I hope it’s so big that it can’t squeeze in here.” The growling and muttering continued, and steadily drew nearer. The boys sat shivering. The cave had grown much colder, they thought, and their teeth chattered. Suddenly the noises ceased and there was a dreadful silence. The rain was still pouring outside, with a steady roar on the rocks, but the boys did not notice that, and it seemed to them that all sounds had stopped. Silently the two sat in suspense, wondering what would happen, whether they would suddenly be conscious of an animal in the cave with them. Then they reflected that the entrance was so small that no large animal could pass through, at least not quickly. They were gazing intently toward the opening, though the darkness was so dense that not even its outline could be distinguished. As they sat, rigid, they realized with a shock that they were looking at two small balls of fire which must be just outside the opening. The fiery globes remained stationary, and colder shivers ran along the boys’ spines. CHAPTER XV A BLOCKADE When the boys saw the two glowing spots of fire in the entrance to the cave, for one sickening moment they imagined that it was something supernatural. They waited tensely for whatever fearful development might follow. “What can it be, Sid?” And Raymond’s voice trembled. “It’s beyond me. Is it outside, or in?”