The Urchin grinned.

"Oh, you girls!" he said. "Who ever heard of gas in a sea cave. What you are smelling is the lamp."

Fiona took the lamp up.

"I'm going to take charge of this myself," she said. "You can carry the treasure."

The Urchin picked up the sack and threw it over his shoulder.

"Go ahead, lady with the lamp," he said, and grinned again. He felt very adventurous. He would rather have liked to be photographed.

With considerable caution, necessitated by the heavy lamp, they climbed the rock barrier and descended into the darkness of the inner cave. The walking was better here; the rounded slippery boulders had given place to a floor of pebbles and sand. Quite a short way from the barrier the wall of the cave curved away in a semicircle on the right, its smooth surface forming a kind of small recess. Fiona swept the recess with her lamp, and on the sandy floor something gleamed back; the Urchin pounced on it and picked it up. It was a gold coin, not the least like any which the children had ever seen. It was, in fact, a doubloon.

"This must be one of them," said the boy exultantly as he pocketed it; "one that got dropped. Come on, it can't be much farther."

But Fiona held the lamp steady and stared at the sand.

"Look at the marks on the sand," she said. "They are like the marks of heavy boxes. The treasure has been here, Urchin, and it's not here now. Someone has been here and taken it, and dropped one piece."

"I don't think so," said the Urchin. "We shall find them a bit farther on."

So they went on, but not very far. For the light of the lamp suddenly fell on a rock wall before them, the end of the cave. And it had ended, not as the other caves do, by the roof growing lower and lower till it meets the floor; it had ended in this huge chamber of high rocky walls.

"So this is the cave that no one has ever reached the end of," said Fiona. "Why, it goes no distance at all."

They retraced their steps to the recess, and then back to the end again, looking on this side and on that for openings, but it seemed quite clear that there were none.

"The boxes must have been carried off by sea," said Fiona.

But the Urchin had an idea.

"No one would try to carry great heavy boxes over the rock barrier,"

he said. "They'd just take the gold out in sacks."

"The barrier may be a rock-fall," said Fiona. "The treasure may all have been cleared out long ago."

And then there came to the Urchin the realization of the fact that he had lost his gun. He turned very red.

"It's a shame," he said angrily, "an awful shame. It was given to me, and someone has taken it. Can't you think where it could be, Fiona?

I'd go _anywhere_ to find it."

Whatever Fiona may have been going to say, her words tailed off into sudden silence. For from beyond the cave wall, as it seemed, sounded again the footsteps which they had heard before; and this time they knew that there was no cave there, and that It was walking through solid rock as if along a road. There was no question this time of any concealment or pretence; both frankly turned tail and made for the rock barrier. Halfway there the Urchin tripped and fell heavily on his head. Fiona put the lamp down and helped him up, dizzy and shaking.

"Can you go on, Urchin?" she said. "If not, I'll try and carry you."

The Urchin looked back into the blackness, unrelieved by any ray of the lamp, which faced the other way. The footsteps were steadily drawing nearer, neither hasting nor staying. What the Urchin may have thought he saw Fiona could not guess; he gave one shriek, slid out of her grasp, and bolted for the rock barrier as fast as his trembling feet would carry him.

For one moment Fiona all but followed him. Then it suddenly came to her that she was responsible for the boy's safety. She never knew afterwards how she managed to do what she did; but she turned, and with the courage of utter desperation--the courage which enables the hen partridge to face the sparrow hawk--stood at bay, swinging up the heavy lamp to see and face whatever should come.

And into the circle of lamplight quietly walked the figure of the old hawker.

The revulsion of feeling was too much for Fiona. She sprang forward and caught the old man's hand and clung to it.

"Oh," she said, "I'm so glad it's you. We heard the footsteps and we were so frightened." The relief of it all was overwhelming; she was almost crying, and went on saying anything, hardly knowing what she said, just for the mere human companionableness of it. "How did you come here? I suppose you came over with Angus in his boat. Of course you would. Then there must be another way into the cave after all, and we couldn't find it."

"And so I frightened you?" said the old man gently, making no effort to withdraw his hand. "Yes, there is another way in." He made no attempt to answer all her questions.

"Urchin," called Fiona, raising her voice. "Urchin, come back; it's all right."

But there was no answer.

"Urchin," she shouted; "Urchin."

But there was no answer save the echoing of the empty cave.

"He was going down to the boat," she said, loyally repressing the fact that the Urchin had bolted. "We must go after him, for he had hurt his head, and I am afraid of his falling again."

They climbed the rock barrier, and made their way to the boat. The boat lay there as it had been left, half ash.o.r.e, with the swell rippling against the stern, and over one thwart the Urchin's jacket, just as he had thrown it down. And the boat was as empty as the cave.

Into Fiona's eyes came a sudden fear.

"He must have fallen again, and be lying somewhere," she said.

They went back, searching every nook and corner of the cave, turning the light into every crevice, under every rock, making a minute examination of the rock barrier; and there was no sign.

And then Fiona broke down.

"He is drowned," she said, and just sat and sobbed.

After a few moments the old man came and sat down beside her. In his gentle voice he said that the Urchin could not possibly be drowned.

The water was quite shallow at the edge, and he was a good swimmer, was he not? And even if he had not been, the swell would have rolled him ash.o.r.e. He himself had no doubt that all would come right.

Fiona ceased sobbing and turned on him.

"Do you know where he is?" she demanded bluntly.

"How would I know when you do not know?" said the old man. "Could I see what you could not see?" And then "Listen."

Down the waterway came voices, and the sound of oars. It was in fact Jeconiah's boat entering the cave.

Fiona caught at the straw.

"He may have swum out to the other boat," she said.

But there was no one in the other boat but Jeconiah and his two men.

They had powerful lanterns, and the boat was full of sacks. Jeconiah himself was purple with suppressed rage and impatience. The moment he could get ash.o.r.e, he waddled up to Fiona and shook the map of the cave in her face, exclaiming, "Remember, if you have found anything it belongs to me and I claim it."

Fiona had only one thought in her mind at the moment, and the foolish impertinence of the little fat man was to her merely so much unnecessary sound. Her answer was "Have you seen the Urchin? We have lost him. Did he not swim out to your boat?" She was almost sobbing again.