Suddenly Gerald uttered a loud exclamation. Jack, glancing at him, saw that he was pointing to a place in the side of the mass and staring at it as though his eyes were about to start out of his head. ’What on earth’s up, old man?’ he asked in alarm. ’Have you got an attack of nerves again, or’—— ’Jack!’ cried Gerald, seizing his chum’s arm, ’d-didn’t you see—didn’t you see them?’ ’Them—what—who?’ asked Jack, bewildered. ’People—men—moving about! I declare that I saw some men moving about inside the—the—thing!’ ’You ’re barmy, my good Gerald! This little astronomical raree-show has been too much for those imaginative nerves of yours. I see nothing. Perhaps you saw shadows thrown by some birds flying overhead.’ ’No, oh no! A thousand times no! I tell you I saw people—two or three—moving about inside that smooth, slippery surface. They were very dim and shadowy, it is true, but they were there. I saw them just as one might see anything through very thick, semi-opaque glass. What does it mean? I tell you it’s uncanny! There’s some strange mystery about it all. This thing is not what it seems to be. What, in the name of all that is wonderful, does it mean?’ Jack looked at the smooth, shining sides which rose from the water and towered up high in the air. But he could see nothing to account for Gerald’s wild words; and he then glanced inquiringly, with real alarm and trouble in his eyes, at Armeath. ’I am afraid,’ said the scientist, with a grave smile, ’that Gerald is letting his exuberant imagination run away with him this morning. I confess I see nothing of the kind he described. It must have been some strange effect of the rays of the sun, which is not very high yet, striking at an angle upon these remarkable, shining sides.’ Gerald shook his head impatiently, but made no verbal reply; and they rowed round and round the phenomenon, without finding anything to satisfy their curiosity. Armeath examined the smooth sides closely, sometimes through a magnifying glass. He even tried to chip off a piece with a hammer and a chisel; but it was so hard that he could make no impression upon it, and so slippery that his chisel glanced off and flew from his hand into the sea. After a good deal of rowing to and fro, and a considerable amount of critical examination, which threw not the slightest light upon the puzzling lump of mystery, it was decided to return to shore for their breakfast. Even over their meal, however, their talk continued to run upon the all-engrossing subject. Jack rallied his chum unmercifully upon the extraordinary statement he had made; but Gerald refused to admit that he might have been mistaken. ’I saw what I told you!’ he persisted doggedly. ’I may be a bit of a dreamer at times, but I don’t "see visions" to that extent. No, there is some awful, inscrutable, incredible mystery about it all! Well, we ’ll wait and see. We shall find out, I suppose, in good time.’