A hundred yards deeper into the mountain there was a confirming repetition of the flash-light picture for the ex-engineer. The two men, walking rapidly now, one a step in advance of the other, passed under another of the overhead light bulbs, and this time Judson, watching for the third man, saw him quite plainly. The sight gave him a start. The third man was tall, and he wore a soft hat drawn low over his face.

"Well, I'll be jiggered!" muttered the trailer, pulling his cap down to his ears and quickening his pace. "If I didn't know better, I'd swear that was Hallock again—or Hallock's shadder follerin' him at a good long range!"

The chase was growing decidedly mysterious. The two men in the lead could be no others than Flemister and the chief clerk, presumably on their way to the carrying out of whatever plot they had agreed upon, with Lidgerwood for the potential victim. But since this plot evidently turned upon the nearing approach of Lidgerwood's special train, why were they plunging on blindly into the labyrinthine depths of the Wire-Silver mine? This was an even half of the mystery, and the other half was quite as puzzling. Who was the third man? Was he a confederate in the plot, or was he also following to spy upon the conspirators?

Judson was puzzled, but he did not let his bewilderment tangle the feet of his principal purpose, which was to keep Flemister and his reluctant accomplice in sight. This purpose was presently defeated in a most singular manner. At the end of one of the longer tunnel levels, a black and dripping cavern, lighted only by a single incandescent shining like a star imprisoned in the dismal depths, the ex-engineer saw what appeared to be a wooden bulkhead built across the passage and effectively blocking it. When the two men came to this bulkhead they passed through it and disappeared, and the shock of the confined air in the tunnel told of a door slammed behind them.

Judson broke into a stumbling run, and then stopped short in increasing bewilderment. At the slamming of the door the third man had darted forward out of the shadows to fling himself upon the wooden barrier, beating upon it with his fists and cursing like a madman. Judson saw, understood, and acted, all with the instinctive instantaneousness born of his trade of engine-driving. The two men in advance were merely taking the short cut through the mountain to the old workings on the eastern slope, and the door in the bulkhead, which was doubtless one of the airlocks in the ventilating system of the mine, had fastened itself automatically after Flemister had released it.

Judson was a hundred yards down the tunnel, racing like a trained sprinter for the western exit, before he thought to ask himself why the third man was playing the madman before the locked door. But that was a matter negligible to him; his affair was to get out of the mine with the loss of the fewest possible seconds of time—to win out, to climb the ridge, and to descend the eastern slope to the old workings before the two plotters should disappear beyond the hope of rediscovery.

He did his best, flying down the long tunnel reaches with little regard for the precarious footing, tripping over the cross-ties of the miniature tramway and colliding with the walls, now and then, between the widely separated electric bulbs. Far below, in the deeper levels, he could hear the drumming chatter of the power-drills and the purring of the compressed air, but the upper gangway was deserted, and it was not until he was stumbling through the timbered portal that a watchman rose up out of the shadows to confront and halt him. There was no time to spare for soft words or skilful evasions. With a savage upper-cut that caught the watchman on the point of the jaw and sent him crashing among the picks and shovels of the mine-mouth tool-room, Judson darted out into the moonlight. But as yet the fierce race was only fairly begun. Without stopping to look for a path, the ex-engineer flung himself at the steep hill-side, running, falling, clambering on hands and knees, bursting by main strength through the tangled thickets of young pines, and hurling himself blindly over loose-lying bowlders and the trunks of fallen trees. When, after what seemed like an eternity of lung-bursting struggles, he came out upon the bare summit of the ridge, his tongue was like a dry stick in his mouth, refusing to shape the curses that his soul was heaping upon the alcohol which had made him a wind-broken, gasping weakling in the prime of his manhood.

For, after all the agonizing strivings, he was too late. It was a rough quarter-mile down to the shadowy group of buildings whence the humming of the dynamo and the quick exhausts of the high-speeded steam-engine rose on the still night air. Judson knew that the last lap was not in his trembling muscles or in the thumping heart and the wind-broken lungs. Moreover, the path, if any there were, was either to the right or the left of the point to which he had attained; fronting him there was a steep cliff, trifling enough as to real heights and depths, but an all-sufficient barrier for a spent runner.

The ex-engineer crawled cautiously to the edge of the barrier cliff, rubbed the sweat out of his smarting eyes, and peered down into the half-lighted shadows of the stockaded enclosure. It was not very long before he made them out—two indistinct figures moving about among the disused and dilapidated ore sheds clustering at the track end of the old spur. Now and again a light glowed for an instant and died out, like the momentary brilliance of a gigantic fire-fly, by which the watcher on the cliff's summit knew that the two were guiding their movements by the help of an electric flash-lamp.

What they were doing did not long remain a mystery. Judson heard a distance-diminished sound, like the grinding of rusty wheels upon iron rails, and presently a shadowy thing glided out of one of the ore sheds and took its place upon the track of the old spur. Followed a series of clankings still more familiar to the watcher—the ting of metal upon metal, as of crow-bars and other tools cast carelessly, one upon the other, in the loading of the shadowy vehicle. Making a telescope of his hands to shut out the glare from the lighted windows of the power-house, Judson could dimly discern the two figures mounting to their places on the deck of the thing which he now knew to be a hand-car. A moment later, to the musical click-click of wheels passing over rail-joints, the little car shot through the gate-way in the stockade and sped away down the spur, the two indistinct figures bowing alternately to each other like a pair of grotesque automatons.