In the same moment the girl’s voice came to him across the pool, mingling with the rushing of great waters.

“The tide is coming up fast.  It won’t be safe much longer.”

“Don’t move!  Don’t move!” he cried back almost frantically.  “It is absolutely safe.  I will swim across and help you if you are afraid.  But wait—­wait just a few moments more!”

She did not urge him.  Her surrender had been too complete.  Perhaps his promise reassured her, or perhaps she did not fully realise the danger.  She waited motionless and the man worked on.

Again there came that sound that was like the report of a distant gun, and the roaring of the sea swelled to tumult.

“Don’t move!  Don’t move!” he cried again.

But she could not have heard him in the overwhelming rush of the sea.

There came a sudden dimness.  A cloud had drifted over the moon, and Knight looked up and cursed it with furious impatience.  It passed, and he saw her again—­his vision, the goddess of his dream, still as the rock behind her, yet splendidly alive.  He bent himself again to his work.  Would that wave never come to veil her in sparkling raiment of foam?

Ah!  At last!  The peace of the pool was shattered.  A shining wave, curved, green, transparent, gleamed round the corner, ran, swift as a flame, along the rock, and broke with a thunderous roar in a torrent of snow-white surf.  In a moment the pool was a seething tumult of water, and in that moment Knight saw his goddess as the artist in him had yearned to see her, her beauty half-veiled and half-revealed in a shimmering robe of foam.

The vision vanished.  Another cloud had drifted over the moon.  Only the swirling water remained.

Again he lifted his head to curse the fate that baffled him, and as he did so a hand came suddenly from the darkness behind and gripped him by the shoulder.  A voice that was like the angry bellow of a bull roared in his ear.

What it said he did not hear; so amazed was he by the utter unexpectedness of the attack.  Before he had time to realise what was happening, he was shaken with furious force and flung aside.  He fell—­and his precious work fell with him—­on the very edge of that swirling pool....

Seconds later, when the moon gleamed out again, he was still frantically groping for it on the stones.  The roar of the sea was terrible and imminent, like the roar of a destroying monster racing upon its prey, and from the caves there came a hollow groaning as of chained spirits under the earth.

The light flashed away again just as he spied his treasure on the brink of the dashing water.  He sprang to save it, intent upon naught else; but in that instant there came a roar such as he had not heard before—­a sound so compelling, so nerve-shattering, that even he was arrested, entrapped as it were by a horror of crashing elements that made him wonder if all the fiends in hell were fighting for his soul.