A fear oppressed him that perhaps this apparent effort of hers and her slow motion were only a ruse to lead him on--that at any moment she might dart from him or sink into her familiar depths.

But this fear he did not heed as long as she remained in sight, and--yes, across the surface of the warm moonlit water he was slowly but surely gaining upon her.
On he swam, making strenuous effort at speed.

He was growing exhausted with the unaccustomed exercise; he knew that his strength would not hold out much longer.

He hardly knew what he hoped or dreamed would come to pass when he overtook the sea-maiden, and yet he swam for dear love, which was more to him than dear life, and, panting, he came close to her.
The sea-maid turned about, and her face flashed suddenly upon him, bright in the moonlight.

She put out a glistening arm, perhaps in human feebleness to ward him off, perhaps, in the strength of some unknown means of defence, to warn him that at his peril he approached her.
Caius, reckless of everything, grasped the white wrist, and, stopping his motion, knowing he could not lie mermaid-fashion with head reared in the water, he turned on his back to float, still holding the small hand in his.