They had got about halfway down the mountain when a thick mist was seen sweeping over the sea from the southward. It came on so rapidly that before they could decide what path to follow they were entirely enveloped in it. They could now only venture to move with the greatest caution; any moment they might arrive at the edge of some frightful precipice similar to those they had before passed. Anxious, however, to escape the cold and damp to which they were exposed on the mountain side, they descended by the only practicable route they could find. The mist every instant grew thicker, and the short day was drawing to a close. In what direction they were going they could not with any certainty tell. At last the captain declared that he would proceed no further. The doctor agreed with him. Just then they saw before them the edge of the forest, which reached up the mountain side to a considerable distance from the shore. They agreed that it would be wise to camp here for the night; and while Willy and Peter cut down some boughs to form a hut, and wood for fuel, the doctor and the captain endeavoured to shoot a few birds for supper. They could hear them singing in the woods in great numbers, but the mist shrouded them from their view till they were close upon them. The birds were, however, so tame that they succeeded in killing a few; and these, with some of the roots which the doctor dug up close at hand, gave them a sufficient meal. As night came on, they made up their fire and crept into their leafy bower for shelter. "I suppose, doctor, we ought, to keep watch," said Willy. "We may have a big tiger-seal poking his nose in among us, or there may be other wild beasts, though we have not seen them." The doctor agreed to the wisdom of this, and when supper was over they drew lots as to who should keep the first watch. It fell upon Willy. After they had sat up some time, the rest of the party went to sleep. Willy had some difficulty in performing his duty, but by running out every now and then to throw a log on the fire he managed to keep his eyes open. As he did so on one occasion, he saw an animal scamper by him. "It looked very like a wolf," he said to himself. He got the doctor's gun to have a shot at it, should it again appear. There was no use, he thought, in waking up his companions. In a short time afterwards he heard a loud bark. He listened. The bark was repeated. "Why, it's a dog. I wonder if there are people in the neighbourhood," he said to himself. "If there are, they will find us out; but they are not likely to be otherwise than friendly. However, when I call the captain I'll tell him to keep a sharp lookout." When at length his watch was over, he roused up Captain Twopenny and told him what had occurred. "Perhaps there may be natives on the island, after all," observed the captain. "Depend upon it, I will not be taken by surprise."