Iris could not remain serious for many consecutive minutes, but she gathered that he was in no mood for frivolity.

"And the shelter--is it a house?" she continued.

"No, a cave. If you are sufficiently rested you might come and take possession."

Her eyes danced with excitement. He told her what he had seen, with reservations, and she ran on before him to witness these marvels.

"Why did you make a new path to the well?" she inquired after a rapid survey.

"A new path!" The pertinent question staggered him.

"Yes, the people who lived here must have had some sort of free pa.s.sage."

He lied easily. "I have only cleared away recent growth," he said.

"And why did they dig a cave? It surely would be much more simple to build a house from all these trees."

"There you puzzle me," he said frankly.

They had entered the cavern but a little way and now came out.

"These empty cartridges are funny. They suggest a fort, a battle."

Woman-like, her words were carelessly chosen, but they were crammed with inductive force.

Embarked on the toboggan slope of untruth the sailor slid smoothly downwards.

"Events have colored your imagination, Miss Deane. Even in England men often preserve such things for future use. They can be reloaded."

"Yes, I have seen keepers do that. This is different. There is an air of--"

"There is a lot to be done," broke in Jenks emphatically. "We must climb the hill and get back here in time to light another fire before the sun goes down. I want to prop a canvas sheet in front of the cave, and try to devise a lamp."

"Must I sleep inside?" demanded Iris.

"Yes. Where else?"

There was a pause, a mere whiff of awkwardness.

"I will mount guard outside," went on Jenks. He was trying to improve the edge of the axe by grinding it on a soft stone.

The girl went into the cave again. She was inquisitive, uneasy.

"That arrangement--" she began, but ended in a sharp cry of terror. The dispossessed birds had returned during the sailor's absence.

"I will kill them," he shouted in anger.

"Please don't. There has been enough of death in this place already."

The words jarred on his ears. Then he felt that she could only allude to the victims of the wreck.

"I was going to say," she explained, "that we must devise a part.i.tion.

There is no help for it until you construct a sort of house. Candidly, I do not like this hole in the rock. It is a vault, a tomb."

"You told me that I was in command, yet you dispute my orders." He strove hard to appear brusquely good-humored, indifferent, though for one of his mould he was absurdly irritable. The cause was over-strain, but that explanation escaped him.

"Quite true. But if sleeping in the cold, in dew or rain, is bad for me, it must be equally bad for you. And without you I am helpless, you know."

His arms twitched to give her a rea.s.suring hug. In some respects she was so childlike; her big blue eyes were so ingenuous. He laughed sardonically, and the harsh note clashed with her frank candor. Here, at least, she was utterly deceived. His changeful moods were incomprehensible.

"I will serve you to the best of my ability, Miss Deane," he exclaimed.

"We must hope for a speedy rescue, and I am inured to exposure. It is otherwise with you. Are you ready for the climb?"

Mechanically she picked up a stick at her feet. It was the sailor's wand of investigation. He s.n.a.t.c.hed it from her hands and threw it away among the trees.

"That is a dangerous alpenstock," he said. "The wood is unreliable. It might break. I will cut you a better one," and he swung the axe against a tall sapling.

Iris mentally described him as "funny." She followed him in the upward curve of the ascent, for the grade was not difficult and the ground smooth enough, the storms of years having pulverized the rock and driven sand into its clefts. The persistent inroads of the trees had done the rest. Beyond the flight of birds and the scampering of some tiny monkeys overhead, they did not disturb a living creature.

The crest of the hill was tree-covered, and they could see nothing beyond their immediate locality until the sailor found a point higher than the rest, where a rugged collection of hard basalt and the uprooting of some poon trees provided an open s.p.a.ce elevated above the ridge.

For a short distance the foothold was precarious. Jenks helped the girl in this part of the climb. His strong, gentle grasp gave her confidence. She was flushed with exertion when they stood together on the summit of this elevated perch. They could look to every point of the compa.s.s except a small section on the south-west. Here the trees rose behind them until the brow of the precipice was reached.

The emergence into a sunlit panorama of land and sea, though expected, was profoundly enthralling. They appeared to stand almost exactly in the center of the island, which was crescent-shaped. It was no larger than the sailor had estimated. The new slopes now revealed were covered with verdure down to the very edge of the water, which, for nearly a mile seawards, broke over jagged reefs. The sea looked strangely calm from this height. Irregular blue patches on the horizon to south and east caught the man's first glance. He unslung the binoculars he still carried and focused them eagerly.

"Islands!" he cried, "and big ones, too!"

"How odd!" whispered Iris, more concerned in the scrutiny of her immediate surroundings. Jenks glanced at her sharply. She was not looking at the islands, but at a curious hollow, a quarry-like depression beneath them to the right, distant about three hundred yards and not far removed from the small plateau containing the well, though isolated from it by the south angle of the main cliff.

Here, in a great circle, there was not a vestige of gra.s.s, shrub, or tree, nothing save brown rock and sand. At first the sailor deemed it to be the dried-up bed of a small lake. This hypothesis would not serve, else it would be choked with verdure. The pit stared up at them like an ominous eye, though neither paid further attention to it, for the glorious prospect mapped at their feet momentarily swept aside all other considerations.

"What a beautiful place!" murmured Iris. "I wonder what it is called."

"Limbo."

The word came instantly. The sailor's gaze was again fixed on those distant blue outlines. Miss Deane was dissatisfied.

"Nonsense!" she exclaimed. "We are not dead yet. You must find a better name than that."

"Well, suppose we christen it Rainbow Island?"

"Why 'Rainbow'?"

"That is the English meaning of 'Iris,' in Latin, you know."

"So it is. How clever of you to think of it! Tell me, what is the meaning of 'Robert,' in Greek?"

He turned to survey the north-west side of the island. "I do not know,"

he answered. "It might not be far-fetched to translate it as 'a ship's steward: a menial.'"