A soft laugh sounded by the controls of the autogyro. The tower at the back of the roof was plain, now that the view was closer. Piloting his ship with uncanny skill, The Shadow picked the space in front of the projecting tower. Like a winged creature from the outer spaces, the autogyro settled amid the trees and came to a perfect landing on the roof of the house.
The wheels rolled forward for a single turn. The ship wavered slightly, then remained still. Nosed almost against the house tower, the autogyro was resting in an area but little larger than its own dimensions.
Motion in the darkness. The Shadow was alighting from the ship. Invisible amid the enshrouding night, he moved forward to the square tower. In agile fashion, this mysterious visitor swung up toward the skylight that Professor Whitburn had left opened in anticipation of his arrival.
TIME had elapsed since Eric Hildrow and his ruffians had entered the house. Down in the hallway beside the outer door, Nuland and two others were holding Professor Whitburn and Stephen against the wall. Hildrow had left the prisoners with Nuland while he had made a trip with Polmore.
The two were returning. They arrived from a doorway that led to the cellar. Hildrow was smiling in his insidious fashion. He stopped to face Professor Whitburn and spoke in his sarcastic tones.
“Polmore has shown me your submarine chamber,” remarked Hildrow. “An interesting room, professor. I understand that you once conducted experiments with torpedoes from that spot. The machines there interested me, even though they are partly dismantled. I also noticed the periscope that you did not remove.
“But most of all” — Hildrow was leering villainously — “I observed that the chamber is practically airtight. Once you and Stephen are locked within that room, your doom will be assured. So, professor, I shall put your submarine chamber to a new use. It will become your tomb.”
Turning to Polmore, Hildrow put a question. Polmore nodded and brought an envelope from his pocket. Hildrow received the envelope and looked at Whitburn.
“A note,” remarked Hildrow. “from Polmore to Bragg. When Bragg returns to-morrow, he will report in your study, as usual. This message will tell him that you have left the island. Bragg will come to New York, to find you at the place designated in the note.
“Do you admire my cleverness, professor? You should. By permitting Bragg to return and leave unmolested, I shall create the impression that all is well on Death Island. I do not care to remain hereabouts with my companions. We shall leave immediately after placing you and your man in the submarine room.
“Ah, yes!” Hildrow leered as he caught a glimmer in the professor’s eyes. “You are thinking of something that you hoped I had forgotten. You had an idea that I had overlooked your cat. Bragg might suspect something if he found the animal here alone. Get the cat, Nuland; take it to the submarine room along with the men.”
WHILE Nuland headed toward the study, Hildrow motioned to the other men. They marched Whitburn and Stephen toward the cellar stairs, where Polmore pointed the way.
As the armed men descended with the prisoners, Nuland appeared with Quex. The tiger-cat was clawing at its captor.
“They have gone down, Nuland,” remarked Hildrow. “Put the cat in the room with them and wait for Polmore. He will give you further instructions. Do exactly as he orders.”
Nuland nodded while he was snatching the cat’s claws from his collar. Then he followed the path that the others had taken. Hildrow spoke to Polmore.
“I shall place this envelope in the study,” growled the plotter. “In the meantime, go down to that submarine room. Give Nuland the signal to kill Whitburn and Stephen. Shoot them down, and allow a couple of bullets for the cat.”
“They can’t escape from that room,” returned Polmore. “Just as you said, chief, they’ll suffocate.”
“I know they haven’t a chance. That does not matter. No one can hear the shots. Kill them; then lock the door. That gang of Nuland’s can stand some target practice. I want killers working for me.
“Watch the job, Polmore. It will do you good. You turned yellow to-night; but I can forget that fact. I shall have other work for you. I want you to be steeled. Proceed with the order.”
With that, Hildrow turned and strolled toward the study. Polmore watched his chief pass along the corridor. White-faced, the traitor stood beside the door. Unused to murder, he was hesitant about giving the grim command to Nuland.
Polmore was yellow. But in his yellowness, he gave thought to his own welfare. As he hesitated, he realized that his position with the chief was none too secure. Hildrow had deliberately ordered the secretary to start the massacre because he wanted to test Polmore’s mettle.
Realizing this, Polmore forced a fierce grin to his lips. Deliberately, the man adopted the attitude of a fiend. Self-encouraged, this tool began to share the evil nature that characterized Eric Hildrow. Polmore turned toward the cellar steps.
So intent was Polmore that he gave no thought to his surroundings. Mumbling furious words, he was staring straight ahead. He did not glance toward the stairway that led to the second floor. Hence he did not see the eyes that were burning from the dim steps.
The Shadow had arrived just after Hildrow’s departure. He had watched the flickering expression that had shown on Polmore’s face. Outside of that observation, The Shadow had, as yet, learned nothing. But his keen study of Polmore was sufficient to tell him that malice was afoot.
The menace had fallen upon the abode of Professor Arthur Whitburn. The old inventor was in danger. Polmore was on his way to complete some evil chain of action. Of that, The Shadow was certain.
As Polmore’s figure started down the cellar steps, The Shadow advanced from darkness. The dim light showed him as a fantastic figure. A being cloaked in black, with slouch hat pulled low upon his forehead. A spectral personage, whose glowing eyes showed vengeance, The Shadow was moving to thwart murder.
Whipping from the folds of the cloak, The Shadow’s hands produced a pair of mammoth automatics. With these weapons in readiness, the black-garbed avenger stalked forth on Polmore’s trail. Descending a flight of curving stone steps, The Shadow closed the gap between himself and Professor Whitburn’s treacherous secretary.
THE SHADOW paused when he arrived at the final turning point. A massive metal door stood open. Beyond it was the submarine chamber. Short steps led down into the pitlike room. A single ceiling light showed the grim scene.
Like victims in a medieval prison, Professor Whitburn and Stephen stood facing the firing squad. Two men were covering them, while Nuland stood ready with another gun.
Polmore had also drawn a revolver. On the lowest step, he was ready to issue Hildrow’s manifesto.
Slowly, The Shadow’s automatics came to aim. The cloaked rescuer was ready. The Shadow knew that Polmore’s command to kill would be the proper signal for his own attack. Stopped on the point of murder, men of crime would be most vulnerable.
“Give them the works!” said Polmore, suddenly. His voice sounded strained. “Kill them, Nuland! The chief said to kill them! Both of them — and the cat!”
The added statement came blurted from Polmore’s lips. Nuland, a professional killer, grinned as he heard it. About to repeat the order to his men — the pair were awaiting his word — Nuland turned to look at Polmore’s whitened face.
There was contempt on Nuland’s features as the man eyed the pale secretary. Then, on the instant, the expression changed. Purely by accident, Nuland had seen beyond Polmore. He had caught the outline of the blackened figure that stood in the doorway to the room.