Rejoining O’Melia, Doc showed the construction man something of interest — pools of a viscous fluid outside the bungalow doors and under each of the windows. Doc had planted these shortly after bringing O’Melia and Jud to the place.
“The prowler walked through this stuff,” he explained. “He failed to notice it because the ground is still damp from the rain.”
“So what?” O’Melia wanted to know.
Doc focused the ultraviolet lantern on the ground. Footprints instantly appeared, glowing with a faint uncanny luminance.
“The chemical the fellow walked through.” Doc elaborated. “He will leave tracks for some time which we can follow by using the lantern device.”
Without more delay, they set out on the trail of the fleeing killer.
They did not get far, however. A man appeared, stumbling madly through the moonlight. In one hand, he carried a slender blade of steel — red and dripping — a sword cane!
The sword cane was almost a necessity to identify Ham. He was no longer the dapperly-dressed lawyer. His garments were wrecked!
“Buttons Zortell led us into an ambush!” Ham rasped. “Monk, Renny, Long Tom, Johnny — all 4 were seized!”
Never was it more apparent than now that Doc was master over his own emotions.
No twinge of feeling altered the metallic set of his features. No catch came into his breathing. Perhaps the flake-gold of his strange eyes assumed a slightly molten hue as he heard the bad news. But that was all — no other change.
“The gang has got our 4 pals?” he said softly as if to be sure.
“They have!” Ham rapped. “They covered us with guns before we knew what was up. They tied us. I cut myself loose with my sword cane. They didn’t know what it was. I tried to help the others. But it was no use. I beat it!”
He snapped red stains off the long, flexible sword cane. The blade made a song like a hard-stricken harp chord.
“Where did this happen?” Doc questioned.
“In a cactus patch on the edge of town. But the last I saw of the outfit, they were headed for the dam with our pals in tow.”
“For the dam?”
“Yes.” Ham shook his head, puzzled. “I expected them to light out for the mountains. But they didn’t! They seemed to think they would be safe from you once they reached the dam.”
“Did you overhear them say that?”
“Sure.”
Doc now took 2-or-3 steps backward…
…and a mesquite clump gobbled him.
“Hey!” gulped Ham and sprang forward. He did not want to be left out of the fight ahead.
But Doc had vanished. He was even now many yards away and traveling swiftly.
“What’ll we do?” O’Melia asked anxiously.
“Twiddle our thumbs,” grunted Ham. “Doc will ring us in when he’s ready for us.”
“But we can get a posse together and rush the dam!” offered O’Melia.
Ham swung his jaw in an abrupt negative.
“Nothing doing! That might spoil Doc’s plans whatever they are.”
The storm still grumbled softly in the distance. The lightning had died away, however, except for an occasional feeble wink. Overhead, a thin and scattered after-storm scud frequently smudged the face of the Moon.
The stiff, palm-like shadow of a yucca seemed to give birth to Doc’s bronze form. He glided through the moonlight. Under his arm was the box-shaped ultraviolet lantern. It sprayed invisible beams at the ground from time-to-time, disclosing footprints which glowed with an unearthly quality.
Doc was trailing the slayer of Jud! The fluorescent footprints led in the direction of the dam.
Men appeared ahead. They were workmen from the dam — excited and a bit frightened. Some nursed bruised heads.
Haunting the shelter of sagebrush and mesquite, Doc heard enough of their animated talk to learn what had happened.
A gang of men — between 12 and 16 in number — had appeared at the dam. Flourishing guns, they had driven off everyone but themselves. Unarmed and not receiving pay as fighting men, the workmen had done the sensible thing and departed without resistance.
“The gang had 4 of Doc Savage’s men as prisoners!” said one laborer.
Doc did not make his presence known but continued on for the dam site. His going was as furtively silent as the stalk of a jungle hunter.
And there had come into his manner something of the fierceness of the wild.
His enemies would be wise to look to their safety!
Quiet gripped the great dam… the quiet that presaged violence.
The gunmen were keeping out-of-sight. Not a shot had been fired in routing the workmen. But they did not know at what moment hostilities might open.
Uneasiness gripped the gang. They swapped weasel glances and muttered under their breaths. They were wondering what had become of their Leader. The fellow had eased himself away from the group.
Had they known the Mastermind was now out on the dam structure itself, they would have been surprised.
Had they known what he was doing, they would have been stricken with TERROR!
The Chief Villain was swathed in his gabardine coat. A bandanna and a cowboy hat completed an effective disguise. The man sat under one of the canvas covers which had been spread over the new concrete. He was conducting some interesting experiments.
Between his knees was a small wooden box. Attached to this was a twisted pair of insulated wires — a small cable dozens-of-yards long. The man scraped the insulation from the free end of the twisted pair and arranged the copper wires so the tips were a fraction-of-an-inch apart.
The sinister experimenter now produced a flashlight. He pointed this at a glass window in the box and pressed the button. A hot electric spark leaped between the naked tips of the copper wires.
The man’s bandanna fluttered with his gusty grunt of satisfaction. The box held a photoelectric cell, spark coil, and batteries. When a light shone upon it, a high-voltage charge of current was hurled through the wire.
If the wires were attached to the proper detonator and embedded in an explosive, a single brilliant light would loosen a blast.
The masked man now proceeded to attach a detonator to the copper strands. This he inserted in a great suitcase of high explosive!
The explosive he lowered down the inside wall of the dam, letting it sink many yards beneath the dirty, muddy water.
The preparations completed, he kneaded his hands gleefully. A bright light — shown in the canyon depths behind the dam — would result in instant destruction of the great edifice.
With a muffled and melodramatic figure in his disguise, the schemer crept along the dam top. He noticed his shoes were leaving muddy stains so he halted and wiped them clean.
In doing this, he discovered a sticky substance. Growling, he cleaned this off also.
If he gave the stuff any thought — if he wondered in the least where it had come from — he never suspected the truth that it was a viscous fluid Doc Savage had planted around O’Melia’s shack. A fluid that had caused him to leave a trail which became uncannily glowing under ultraviolet rays!
The gang was relieved to see its Leader. The wait had rasped somewhat on their nerves.
“What’re we hangin’ around here for?” snarled Buttons Zortell. “Blazes! We’re wastin’ good time! Time we could be usin’ to make a getaway!”
“Shut up!” grated the masked man. “Don’t question my orders!”
“What’re we waitin’ on, then?” Buttons was too uneasy to be bulldozed easily.
“I have been setting a trap,” smirked the voice behind the bandanna.
“What kind of a trap?”
“One that is perfect! One that could not be better! Your part of it is to decoy Doc Savage down to the canyon bottom beneath the dam.”