"Not much chance for anybody who went over," remarked Gaunt, moving nearer. "Not much. Don't stand too close," replied Percy. "You see, the men put in a stake, and rigged up a rope, meaning to go down and explore; but they will have to wait till something has been done before they can make use of it." "What will they do?" asked Virgie, with interest. "Pump air down, I think, and force the bad gas upwards," replied Percy, who was in his element, showing and explaining. Gaunt stood on the plank near the hole, gazing at it as if it fascinated him. His hands were in his pockets. Virgie had made a little movement when he first approached it, putting out her hand as if to grasp his arm. She checked herself, for since his rebuff she had never touched him. But as he still stood there, seeming lost in his own thoughts, some kind of dread fell upon her. "Osbert," she said. He turned sharply at the sound of her voice, and moved towards her. "I believe my--my shoe-lace has come untied," said she. It was the first thing that occurred to her to say, and she knew it was a lame excuse. He looked so intently at her that she almost thought he was aware that it was a pretext merely. Never before had she asked him to render her any such small personal service. "Lean against the wall, and give me your foot," said he. "I'll do it up." "Thanks. The--the air is rather close in here, isn't it?" she faltered, as she went to stand against the cave side. "Will you take me out? I feel a bit faint." "We shall all go out in a minute or two," was his reply, as he knelt upon the plank at her feet. He tried to steady himself as he bent over his task. He had seen something in her eyes which shook his purpose--a dawning anxiety, or fear, or.... Was that all? Was there not more? He could not be sure. But, if her suspicions were awake, he might have to let this chance go. The cave echoed to Joey's loud, jolly laugh. She and Gerald were standing upon a plank which see-sawed slightly, and it amused her to make it move up and down. "Don't play the fool there, Joe," said Ferris sharply. "This place is really not safe, you know. You and Mrs. Gaunt had better creep out again. Come along, there's nothing to see." He took her somewhat roughly by the arm. Her weight, suddenly removed from the plank, caused Gerald, who was at the further end, to stumble. He had been balanced upon one foot, and the uneven nature of the rocky floor gave him no place upon which to put the other foot down. It went into a hollow, quite a foot in depth. He gave a lurch, in the effort to reach the next plank, which was not quite near, and came down with all his weight upon one edge of it. It turned over, throwing him completely off his balance. He staggered, slipped, and before Joey had time to shriek, was over the edge of the poisonous gulf and had disappeared.