Steve had been down there on numerous occasions and every inch of the ground was familiar to him. Upon leaving the cage he made his way through the dark, damp tunnels, whistling as he stepped briskly along. He could not imagine what Mr. Penton could want of him down there, for if anything were wrong with the pumping system it was a matter for the engineering department and not for a track inspector. Turning the last bend in the sub-level, Push began to move with more caution. A moment more and he caught sight of the big water pipes winding up through the roof of the level. "I wonder where Mr. Penton is?" muttered the lad, stepping out on a plank platform. As he did so a wave of dampness that almost chilled him swept up from the dark depths of the last level. An open space extended from the floor down to the level itself and from this soundings were occasionally taken to determine the depth of the water. The lead line hung from a peg driven into a crevice in the rock. Steve noted that the line was dry. "That is curious. Mr. Penton evidently has not made a sounding. I should have thought he would have done so if he had reason to think the water was not being pumped out as fast as it should be." Rush raised his voice and called out the name of the superintendent. Only the echo of his own voice came back to him. "That's queer," decided Steve. "But, of course, he did not telephone me from here. He probably is on one of the levels above this. I will wait." Resuming his whistling, the lad began pacing back and forth on the planking, having stuck his candlestick back on his miner's hat. The young inspector had been waiting for fully half an hour, but not a sign of the superintendent did he see. "Well, this is getting rather tiresome," he said, pausing to listen to the rhythmic click of the pumps that his ears could faintly catch. "I think I will amuse myself by sounding the water level." The lad took down the rope, to one end of which a piece of lead had been attached, spun the weighted end a few times about his head, letting it fly out into the darkness, listening intently as the line ran swiftly through his hands. A distant splash followed a few seconds later, whereupon the line gave out not quite so rapidly. "It's down," nodded Steve. He leaned over the edge to pull the line in without drawing it over the edge of the planking, so that he could the better see that mark of the water on the rope. "Gracious, I should hate to take a swim in that hole," said the Iron Boy, with a laugh. He stopped suddenly. Steve thought he had heard something behind him. "Is that you, Mr. Penton?" he asked, turning and peering into the darkness. There was no reply. "I must be getting the creeps," said Steve, beginning to whistle as he hauled in the line. "Wha--what--here, let go of me. Let----" Some invisible force behind had put a sudden pressure upon Steve Rush. He was being rapidly shoved toward the edge of the platform.