The clock on Sherwood Mayo's mantel was nearing two o'clock. It brought no comfort to two bound men who rested on the floor. One was Jeremiah Benson. The other was Louie, the Filipino. The Shadow had surprised Mayo's servant. He had clicked handcuffs on the wrists of both his captives. Standing above the prisoners, The Shadow was a tall figure of black. Jeremiah Benson, staring upward, could barely detect the gleam of two burning eyes beneath the masking hat. A laugh came from the hidden lips.

"Your crimes are at an end!" came a sinister, jibing voice. "You have lived too long, Jeremiah Benson. You are waiting now — waiting the arrival of the only man to whose instructions you have ever submitted. Sherwood Mayo will be here soon!"

"I don't know Mayo," snarled Benson.

The Shadow ignored the protest.

"I divined your game long ago," said The Shadow. "I have heard of your past doings, Benson. You were a man who specialized in blackmail and in murder — you and your evil henchman, Grady. Blackmail was preferable. Murder was useful — when necessary.

"You finally encountered one man who thwarted your schemes — Sherwood Mayo. But he offered you a greater field.

"Backed by his millions, you were to embark upon a greater career. But first, Mayo had work for you to do. His hands were not clean. There were persons who knew too much about him.

"One was Herbert Brockley. He eluded you. So his murder was arranged in France, through hired assassins. But Brockley, fearing his end, gave important papers to a man named Wallace Powell.

"Those papers were dangerous for Mayo. Powell knew Sidney Delmuth — a newcomer in the blackmail ring — an agent whom Mayo himself had provided. Through Delmuth, a meeting was arranged between you and Powell.

"Ten thousand dollars for his information. But Powell never received his money. He knew too much. Grady killed him.

"By mistake, Grady murdered an innocent victim. There was another man, who escaped your weakened bridge. You left him in a burning house. He was rescued. That is news to you!

"Grant Chadwick knew facts concerning Mayo. He also possessed interests which Mayo coveted. Grant Chadwick's death was cleverly contrived by Delmuth. The old man's nephew was the killer. Like Delmuth, Denby Chadwick has paid the penalty.

"One more remained. Paul Hawthorne. He knew less than the others regarding Mayo's ways. But he knew too much. So a killing was arranged here tonight.

"The cleverest part of all the scheming was the arrangement between Mayo and Delmuth.

I discovered that one night when Delmuth went to Mayo's home. He took an envelope with him.

"After leaving Mayo's home, he removed a paper from the envelope and destroyed it.

There was just one inference; Delmuth took a message to Mayo and brought away another; Mayo removed the first and put the second in its place. I saw through that scheme."

Benson was still glaring, but the amazed look in the old man's eyes showed that The Shadow's statements were correct.

"Delmuth and Mayo!" said The Shadow. "Pretended enemies! Actually, the brains of a blackmail ring, beginning operations on a tremendous scale. Eliminating those who might interfere.

"You, Benson" — the voice was ironical — "were but a tool in their hands. A tool, for them; just as Grady was a tool for you."

Half rising, Jeremiah Benson spat curses at the man in black. The Shadow laughed. The clock on the mantel chimed twice.

Turning, The Shadow strode toward the door. Benson wondered at the action. The Shadow had performed it before. Returning, The Shadow spoke final words.

"Mayo will be here tonight," he said. "He, too, is playing some clever game. But he will come. Let him come."

An automobile was driving up to the door of the lodge. The Shadow went to the hall and was obscured in the darkness.

A man was approaching. The door opened. Harry Vincent stopped short as he heard a low, weird whisper.

To Harry, it was a voice that he had heard before. It was a voice that he obeyed — the voice of The Shadow.

Harry listened while he heard instructions. Then he walked inside, alone. He saw no one as he passed through the hall, but as he entered the living room, he heard a sound from outside.

Someone was driving away in the car.

The Shadow had gone. His agent was in charge, awaiting the arrival of Sherwood Mayo.

Harry had met with temporary disaster that night. The wrecking of the car had delayed him, but he had managed to obtain another automobile. He had arrived late — but in time to be of service to The Shadow. Harry could not understand The Shadow's presence here, for he knew that The Shadow had been in New York that evening. He did not know of the flying field near Brookdale, where an automobile had been waiting. The Shadow had come by air.

Sherwood Mayo had managed to mislead The Shadow by flying to Virginia. But Mayo could not know that The Shadow was here at Greenhurst. Soon — if The Shadow divined correctly — Mayo would return, to find a trap.

Harry continued his vigil. Then, from far away, came the thrumming of an airplane motor. Harry drew an automatic from his pocket. He went to the side door of the lodge, and looked out over the landing space, where the searchlight glared.

The roaring became terrific. A plane swooped down from the sky and rolled along the ground. It taxied back toward the lodge.

Two men clambered from the ship. Sherwood Mayo and Fleming were approaching.

Harry waited. He was ready for a double capture. But he had not reckoned with the cunning of Sherwood Mayo.

The millionaire had one unalterable rule. Whenever the plane arrived, Louie awaited in the doorway, clad in his white coat. This was a detail that had escaped Stuart Bruxton's observation. Sherwood Mayo was wily, and he sensed danger. He saw the opened door, but did not see the man hidden in the darkness. Harry was awaiting his close approach.

Mayo, acting upon a sudden hunch, slipped his hand into his coat pocket. As he neared the door, he dropped to the ground and fired a shot at the open door. Fleming duplicated his action. The shot was a lucky one. It struck Harry in the shoulder.

Gamely, Harry tried to return the fire. His shots went wide. He staggered back from the door as Mayo launched a volley of shots.

Harry stumbled through the hall, instinctively clutching his left shoulder. Mayo's lucky shot had wounded him. Crippled, Harry knew that retreat was the only course. He gained the front door and staggered out just as Mayo and Fleming arrived.

More bullets spattered the door. It was Fleming who was shooting. Sherwood Mayo had gone to the aid of Benson and Louie.

Knowing that an attack would be useless, Harry crept along the side of the house, determined to prevent the escape of the enemy before the arrival of The Shadow. He was grimly determined to do his utmost, despite the painfulness of his wound.

Reaching the back of the house, Harry laid low. Then, gazing out toward the landing field, he saw the four men appear from the other side of the lodge.

Benson and the Filipino were being rushed to safety by their rescuers. Raising his right hand, Harry fired. He saw the handcuffed Filipino stumble and fall.

Harry fired again. Mayo turned and shot at the corner of the house. A bullet whistled by Harry's head. Fleming was helping Louie on toward the plane. Mayo was Harry's target now.

The millionaire seemed to possess a charm against bullets. Every shot that Harry fired went wide. Mayo's bullets were nicking the corner of the house, too close for safety.

Harry dropped flat and waited. Mayo turned and hurried toward the plane. Harry pointed his gun and coolly pressed the trigger. The calculated aim proved to be of no avail. The gun was empty!

There was no chance now to stop the fleeing men. They had reached the plane. Fleming was helping Benson and Louie into the cabin from the other side. Sherwood Mayo had reached the safety spot. Desperately, Harry tried to reload his gun; but his left arm was numb and helpless. While he attempted his painful task, he heard the roar of the airplane motor. The big propeller was whirling, and the ship was moving along the ground, away from the house.

It took off in the glare of the searchlight, carrying its passengers away from the danger spot. Harry chided himself for his inability to prevent the escape. The return of The Shadow would be useless, now!

In the cabin of the fleeing plane, Sherwood Mayo was examining the wound that Louie had received. Harry's shot had clipped the man's hip.

The plane was high above the ground, rising away from Greenhurst. It swerved suddenly; Mayo, glancing from the window of the cabin, saw the cause.

Coming at an angle was another plane, heading directly for the fleeing ship!

Fleming, up ahead, had seen the menace. A skilled pilot, he recognized the danger. He thought, at first, that there would be a crash of planes. Then, as the other ship approached, bullets from a machine gun whirred through the fuselage of Sherwood Mayo's plane. It was The Shadow who had opened the attack!

Fleming saw one method of escape. The Shadow was approaching from the right.

Fleming went into a steep left bank to avoid the attacking plane.

Above the roar of his ship's motor, Mayo, horrified, heard a peculiar snap. Then came a sound like the rending of cloth.

The left wing fell from the millionaire's plane. The right wing swung straight upward in the air. Whirling like a broken toy, the escaping plane hurtled downward!

It crashed amid the trees. The passengers and the pilot were buried in the wreckage. Not one survived the crash. Sherwood Mayo and his evil crew had met their doom!

Harry Vincent, propped in bed with a bandaged shoulder, read the newspaper accounts the next day. There were three front-page stories in the New York journals.

One told of the murder of Sidney Delmuth, whose killer, Denby Chadwick, had committed suicide. No motive for the tragedy had been discovered.

Another account told of a strange attack of gunmen who had invaded a cottage in Massachusetts, only to lose their lives at the hands of an unknown protector who had disappeared from the scene. The third described the crash of Sherwood Mayo's plane. It had been heard by farmers, who had investigated.

An old man — as yet unidentified — and Mayo's Filipino servant were in the plane, handcuffed. It was supposed that they had attempted a robbery at Mayo's home, and that the millionaire had captured them.

Why he had been taking the malefactors away in his plane, however, was a mystery. That was all. The important links were missing. Nothing was said of Stuart Bruxton, stranded in Virginia. No word appeared to tell how Harry Vincent, wounded, was brought to New York in the cabin of a plane.

For that plane was a mystery ship. It had come from nowhere; and had disappeared as mysteriously as the man who had piloted it.

The Shadow had stepped from the dark to destroy the blackmail ring — and to the dark he had returned!