which stretched itself upward like a cathedral window on the other side of the lake.
"It frightens me," said Mrs. Cliff. "To be sure, this water was our salvation, for we should have been dead by this time, pirates or no pirates, if we had not found it. But it is terrifying, for all that. We do not know how far it stretches out into the blackness, and we do not know how far down it goes. It may be thousands of feet deep, for all we know. Don't go so near the edge, Ralph. It makes me shudder."
When the little party had returned to the cavern, the captain and the two ladies had a long talk about the lake. They all agreed that the existence of this great reservoir of water was sufficient to account for the greenness and fertility of the little plateau outside. Even if no considerable amount of water trickled through the cracks in the rocks, the moisture which arose from the surface of the water found its way out into the surrounding atmosphere, and had nourished the bushes and vines.
For some time they discussed their new-found water-supply, and they were all glad to have something to think about and talk about besides the great danger which overhung them.
"If it could only have been the lake without the Rackbirds," said
Mrs. Cliff.
"Let us consider that that is the state of the case," remarked Edna. "We have the lake, and so far we have not had any Rackbirds."
It was now nearly noon, and the captain looked around for Ralph, but did not see him. He went to search for him, and finding that the boy had not passed Maka, who was on watch, he concluded he must have gone to the lake. There was no reason why the restless youth should not seek to enliven his captivity by change of scene, but Captain Horn felt unwilling to have any one in his charge out of sight for any length of time, so he went to look for Ralph.
He found no one on the rocky shelf. As there had been little reason to expect a water attack at this hour, Mok had been relieved from guard for a meal and a nap. But as Ralph was not here, where could he be? A second glance, however, showed the captain the boy's clothes lying close by, against the upright side of the rock, and at that moment he heard a cry. His eyes flashed out toward the sound. There on the other side of the water, sitting on a bit of projecting rock not far from the great opening in the cave, he saw Ralph. At first the captain stood dumb with amazement, and he was just about to call out, when Ralph shouted again.
"I swam over," he said, "but I can't get back. I've got the cramps. Can't you make some sort of a raft, and come over to me! The water's awfully cold."
Raft, indeed! There was no material or time for anything of the kind. If the boy dropped off that bit of rock, he would be drowned, and the captain did not hesitate a moment. Throwing aside his jacket and slipping off his shoes, he let himself down into the water and struck out in Ralph's direction. The water was, indeed, very cold, but the captain was a strong swimmer, and it would not take him very long to cross the lake at this point, where its width was not much more than a hundred feet. As he neared the other side he did not make immediately for Ralph. He thought it would be wise to rest a little before attempting to take the boy back, and so he made for another point of rock, a little nearer the opening, urging the boy, as he neared him, to sit firmly and keep up a good heart.
"All right," said Ralph. "I see what you are after. That is a better place than this, and if you land there I think I can scramble over to you."
"Don't move," said the captain. "Sit where you are until I tell you what to do."
The captain had not made more than two or three strokes after speaking when his right hand struck against something hard, just below the surface of the water. He involuntarily grasped it. It was immovable, and it felt like a tree, a few inches in diameter, standing perpendicularly in the lake. Wondering what this could be, he took hold of it with his other hand, and finding that it supported him, he let his feet drop, when, to his surprise, he found that they rested on something with a rounded surface, and the idea instantly came into his mind that it was a submerged tree, the trunk lying horizontally, from which this upright branch projected. This might be as good a resting-place as the rock to which he had been going, and standing on it, with his head well out of the water, he turned to speak to Ralph. At that moment his feet slipped from the slimy object on which he stood, and he fell backward into the water, still grasping, however, his upright support. But this did not remain upright more than an instant, but yielded to his weight, and the end of it which he held went down with him. As he sank, the captain, in his first bewilderment, did not loosen his grasp upon what had been his support, and which still prevented him from sinking rapidly. But in a moment his senses came to him, he let go, and a few downward strokes brought him to the surface of the water. Then he struck out for the point of rock for which he had been aiming, and he was soon mounted upon it.
"Hi!" shouted Ralph, who had been so frightened by the captain's sudden sinking that he nearly fell off his narrow seat, "I thought something had pulled you down."
The captain did not explain. He was spluttering a little after his involuntary dive, and he wanted to get back as soon as possible, and so wasted no breath in words. In a few minutes he felt himself ready for the return trip, and getting into the water, he swam to Ralph. Following the directions given him, the boy let himself down into the water behind the captain, and placed his hands upon the latter's hips, firmly grasping the waistband of his trousers. Then urging the boy not to change his position, nor attempt to take hold of him in any other way, the captain struck out across the lake, Ralph easily floating behind him.
When they stood upon the shelf on the other side, and Ralph, having rubbed himself down with the captain's jacket, put on his clothes, Captain Horn rather sternly inquired of him how he came to do such a foolish and wicked thing as to run the risk of drowning himself in the lake at a time when his sister and his friends had already trouble enough on their minds.
Ralph was sorry, of course, that the captain had to come after him, and get himself wet, but he explained that he wanted to do something for the good of the party, and it had struck him that it would be a very sensible thing to investigate the opening on the other side of the lake. If he could get out of that great gap, he might find some way of climbing out over the top of the rocks and get to the place where his flag was, and then, if he saw Mr. Rynders coming, he could wave it. It would be a great thing if the people in the vessel which they all expected should see that flag the moment they came in sight of the coast. They might get to shore an hour or two sooner than if they had not seen it.
"If the cramp in this leg had kept off five minutes longer," he said, "I would have reached that big hole, and then, if I could have climbed over the top of the rocks, I could have come down on the other side to the front door, and asked Maka to get me my clothes, so I would not have had to swim back at all."
"That will do," said the captain. "And now that you are dressed, you can go inside and get me that woollen shirt and trousers that I use for a pillow, for I must take off these wet things."
When the boy came back with the clothes, the captain told him that he need not say anything to his sister or Mrs. Cliff about the great danger he had been in, but before he had finished his injunction Ralph interrupted him.
"Oh, I have told them that already," said he. "They wanted to know where I had been, and it did not take a minute to tell them what a splendid swimmer you are, and how you came over after me without taking as much as two seconds to think about it. And I let them know, too, that it was a mighty dangerous thing for you to do. If I had been one of those fellows who were not used to the water, and who would grab hold of any one who came to save them, we might both have gone to the bottom together."
The captain smiled grimly. "It is hard to get ahead of a boy," he said to himself.
It was late that
