“Frank, are you there?”

“Yes, Andy. Give me your hand.”

The two brothers spoke softly. It was in the darkness of the cave, for they had both released the pressure on the springs of their portable lights to make the little dry batteries last as long as possible. It was several minutes after the first awful discovery of the incoming tide, and they had maintained a silence until the younger lad, unable to longer endure the strain, had called out.

Silently they clasped hands in the blackness.

“Frank, do you—do you think there’s any way out?”

“Why, of course there is, Andy. All we’ve got to do is to wait a while, and someone will surely come to our rescue. Father and mother know we started for this island, and if we don’t get home soon they’ll start a searching party after us.”

“Yes, but the rising tide, Frank. We—we may drown.”

“Nonsense. The water can’t get very high in here. We’ll simply go to the highest part of the passage, and wait until the tide goes out. That won’t be so very long. What makes me mad, though, is to think how that man fooled us. That was his object all along. He wanted to get us in here so he could drop that rock across the opening and have us caged.”

“Can’t we try to get out?” asked Andy. All his usually joyous spirits had departed. He was very much subdued now, and in the momentary flash of his light, which he permitted himself, Frank saw that his brother was very pale.

“Of course we’ll try!” exclaimed the elder lad, with all the assurance he could put into his voice. “Perhaps we can manage it, too. Let’s have a try. It’s of no use to do it here. We must go back to where he pushed down the rock. Perhaps it isn’t in as tight as we thought at first. Come on. But don’t use your light. Mine is enough, and we must save them as long as we can.”

By the gleam of the single electric torch they made their way back. Soon they were at the rock which made them prisoners. It loomed grim and black in the semi-darkness.

“The water’s higher,” said Andy, in a low voice. Frank had noticed that, for it now reached to his ankles as he splashed his way back along the passage. But he had said nothing, hoping Andy had not observed it.

“Yes,” said the older boy cheerfully, “it’s bound to rise until the tide is at flood, and then—why, it will go down again—that’s all.”

“But suppose it fills this cave?”

“Nonsense! It can’t. I’m not going to suppose anything of the sort. Now come on. Let’s see if we can move this rock.”

Together they pressed on the stone with all their strength. They might as well have tried to budge the side of a mountain. The rock was firmly wedged in place.

“It’s no use,” spoke Andy, in a dull, hopeless tone.

“Oh, don’t give up so easily,” urged his brother. “If we can’t do it one way, we may another. See, it has slid down in a sort of groove. Only a little ridge of rock on either side holds it in place. Now if we can break away those upright ridges, which are like the pieces on a window sash up and down which the window slides, we may be able to push the rock out. Let’s try. Use your knife and take a rock for a hammer.”

Frank placed his torch on a ledge of roc............