The reason for the interruption came suddenly to Harry Vincent’s ears.
From somewhere, in the distance, the thrum of a motor was announcing the approach of what could be only a ship of the air. That sound brought joy to Harry Vincent. It might mean that the Shadow was coming to this spot!
But as Harry thought, he could not repress a groan. Don Chalvers had made preparation for such an attack. The Shadow was coming into the power of the black ray!
CHAPTER XXVIII. THE FINAL STROKE
UPON a flat roof, beneath which Harry Vincent still remained a prisoner, Goldy Tancred and Don Chalvers were standing in a hazy gloom. It was still dark here, close to the ground, but the sky above was tinged with early dawn.
Beside the two men stood the pivoted projector that could cast its dread black ray. Goldy Tancred, growling, was staring toward the sky, while Don Chalvers — again playing the part of Hobbs — was ready with the machine.
“There he comes!” snarled Goldy, pointing high above the horizon. “Be ready. When he gets closer, you can spot him!”
An oddly shaped plane was visible in the pale hues of dawn. Hovering as it approached, the ship revealed spinning blades that whirled like a windmill.
That craft told well who piloted it. The Shadow was arriving in his autogyro!
“Good,” snorted Goldy. “That ship of his can’t move as fast as the biplane you knocked off. Give him the ray when he gets closer. It’s The Shadow — if we get him—”
The big shot did not conclude the statement. He was watching the progress of the ship, and he left his companion to understand that the end of The Shadow would mean the finish of all possible attack or pursuit.
The autogyro came on. Don Chalvers was waiting. He could see that the pilot was picking out the spot that he wanted.
The Shadow had found the connection between Chalvers and the ray. He knew that the flight which had baffled the police must have ended here.
Thus the criminal engineer bided his time. The black-faced searchlight pivoted upward. Still, Chalvers waited, until the moment when the autogyro would be in perfect range. The ship seemed to pause in air — not quite directly above the spot where the two villains were waiting.
“Give it to him!” snarled Goldy.
The autogyro was descending as the big shot gave the order. Less than a thousand feet above, The Shadow had picked out the whiteness of the flat-topped building in back of the old house which belonged to Don Chalvers.
Click!
The black ray cut a widening swath up toward the dawning sky. Just as a searchlight cleaves the night, so did this stream of darkness carve through light. The autogyro was blocked out by the great circle of blackness. The thrum of the motor ceased.
“That ends The Shadow,” announced Goldy Tancred. “Watch him come plopping out of there the same way the biplane crashed. His motor’s gone!”
The two men waited. As their eyes looked upward, they could see no result. The autogyro was lost in the path of blackness. It was vanished as completely as if it had disintegrated within the folds of the black hush.
Seconds went by. Goldy emitted a puzzled growl as he turned to Chalvers. In the dimness beside the black ray, Goldy saw a sudden expression of understanding appear upon his companion’s face.
“He’s coming downward in the ray!” cried the engineer. “He’s guiding himself inside the blackness. That autogyro needs no power — the blades above it resist the air!”
“He’s heading… here?” gasped Goldy. “You mean… you mean he’s dropping straight toward us?”
“Yes!” screamed Chalvers. “We can’t stop him now. He’ll land — right here—”
As the engineer broke away from the side of the black-ray machine, a shape bulged out of the darkness.
Wings and wheels smashed downward toward the roof. The body of the autogyro landed forcibly upon the black-faced projector.
The machine crackled beneath the impact. The black ray ended. Don Chalvers, too late in his leap for safety, was smashed beneath the right wheel of the gyro as it jounced away from the apparatus which it had shattered.
Goldy Tancred saw his companion fall. With an ugly snarl, he whipped out his revolver. He saw a form in black bounce from the right of the thudding autogyro. Goldy fired, knowing that he faced The Shadow.
The big shot missed the swaying body as it slouched back into the cockpit of the autogyro. Then, as the wheels joggled the ship back and forth, Goldy raised his gun to shoot again.
An automatic spoke before the big shot pressed the trigger. The Shadow, recovering from the bumpy landing, had fired in reply, to meet the menace of Goldy Tancred. With a snarling groan, Goldy staggered backward and sprawled upon the flat roof.
The Shadow, tall and sinister, alighted from the autogyro. He bent above the bodies of the men who had sought to resist him. Goldy Tancred had a bullet through his heart; Don Chalvers, crushed by the impact of both wheel and jouncing body, was coughing out his last breath.
Through the last gloom of early night, a clinging darkness that held to the ground despite the approach of dawn, The Shadow descended through an opening in the roof. In the room below, he found the bound form of Harry Vincent. Quickly, he released his agent and drew Harry up the stairs toward the roof.
Slumped in the cockpit of the autogyro, Harry Vincent could scarcely believe that the rescue had been so suddenly effected. He heard the motor hum; with spinning fan now motorized, the autogyro rolled across the roof and took off into the lightening sky.
High above, it seemed to hover. Beneath lay the whiteness of the roof, now visible in the growing light of day. Upon it were two blackened, sprawled-out shapes that lay beside the glistening shattered hulk of a broken-up apparatus.
The ray of darkness would never again be projected by the fiends who lay beside their shattered machine. The power of the black hush had been ended.
With the final stroke, The Shadow had brought doom to the last of those who had plotted amazing crime.
Don Chalvers, the creator, and Goldy Tancred, the instigator, were dead.
The secret of the black hush had been solved, and its weird force had been ended through the mighty strength of The Shadow!