It was not more than four feet deep, beautifully carpeted with sand, and secluded by rocks on all sides.  Not the tiniest crab or fish was to be seen.  It provided an ideal bath.

Iris was overjoyed.  She pointed towards their habitation.

“Mr. Jenks,” she said, “I will be with you at tea-time.”

He gathered all the tins he was able to carry and strode off, enjoining her to fire her revolver if for the slightest reason she wanted assistance, and giving a parting warning that if she delayed too long he would come and shout to her.

“I wonder,” said the girl to herself, watching his retreating figure, “what he is afraid of.  Surely by this time we have exhausted the unpleasant surprises of the island.  Anyhow, now for a splash!”

She was hardly in the water before she began to be afraid on account of Jenks.  Suppose anything happened to him whilst she was thoughtlessly enjoying herself here.  So strongly did the thought possess her that she hurriedly dressed again and ran off to find him.

He was engaged in fastening a number of bayonets transversely to a long piece of timber.

“What are you doing that for?” she asked.

“Why did you return so soon?  Did anything alarm you?”

“I thought you might get into mischief,” she confessed.

“No.  On the other hand, I am trying to make trouble for any unwelcome visitors,” he replied.  “This is a cheval de frise, which I intend to set up in front of our cave in case we are compelled to defend ourselves against an attack by savages.  With this barring the way they cannot rush the position.”

She sighed.  Rainbow Island was a wild spot after all.  Did not thorns and briers grow very close to the gates of Eden?

On the nineteenth day of their residence on the island the sailor climbed, as was his invariable habit, to the Summit Rock whilst Iris prepared breakfast.  At this early hour the horizon was clearly cut as the rim of a sapphire.  He examined the whole arc of the sea with his glasses, but not a sail was in sight.  According to his calculations, the growing anxiety as to the fate of the Sirdar must long ere this have culminated in the dispatch from Hong Kong or Singapore of a special search vessel, whilst British warships in the China Sea would be warned to keep a close lookout for any traces of the steamer, to visit all islands on their route, and to question fishermen whom they encountered.  So help might come any day, or it might be long deferred.  He could not pierce the future, and it was useless to vex his soul with questionings as to what might happen next week.  The great certainty of the hour was Iris—­the blue-eyed, smiling divinity who had come into his life—­waiting for him down there beyond the trees, waiting to welcome him with a sweet-voiced greeting; and he knew, with a fierce devouring joy, that her cheek would not pale nor her lip tremble when he announced that at least another sun must set before the expected relief reached them.