He made no answer. He could not tell her that if one person had already lost his life through his means he had saved another's life, which, but for him, must have perished. He was not at all clear himself on the merits of the case; neither was it one to discuss with a child.
'Come and see the last of these caves,' he said, rousing himself. 'It is called the Mermaid's Cave, perhaps because it is the prettiest of them all. It has an echo you may like to hear.'
A very narrow passage connected the Cave of the Silver Sand with the Mermaid's Cave, and a pool of water filled it which reached to Jack's knees. Before entering it, Jack lighted a candle-end he had brought in his pocket, and put it into Estelle's hand.
'Hold it up high as we go along,' he said. 'I shall have to carry you; the water is too deep for you to wade through, but the cave is worth seeing as we step into it.'
And so it was. Estelle uttered a cry of delight as its beauties broke upon her. The roof was white with stalactites of the strangest and weirdest shapes, which reflected the light of the candle from their wet surfaces. A stream of water was flowing silently down one side of the sandy floor and into the pool they had crossed, which Jack told her was called the 'Rift.'
'I'll show you one of the wonders of this cave,' he said, as he drew her to one side. 'Now listen.'
In a clear, rich voice he sang a few notes, and in a moment a burst of harmony broke out, full and grand as the organ in a cathedral. The sweet tones echoed among the stalactites, lingering as if loth to die.
Estelle gasped. She had never heard anything like it. 'Again, again!' she whispered.
Once more the sailor's rich voice rang through the silent caves, and once more the echoes took up the chord in a flood of melody which, surged over their heads as the little girl and the sailor stood motionless, listening till the last tones trembled into silence. Even then they did not speak for some moments.
'I could listen to it for ever,' said Estelle, drawing a deep breath.