SNEAKS RUBIN was obeying his master’s instructions. He had become conspicuous in the underworld. Sneaks was a well-known character, but he usually kept to himself. Now he was traveling the rounds.

He cronied with gangsters whom he had known and chatted with them in places where he might be overheard. His conversation dwelt on a particular subject. Who had last seen Clipper Tobin before he was bumped off?

Sneaks was keenly observant. All the time that he was apparently concerned in talk, he was watching.

This was the third night that he had been thus engaged, for he had started on his campaign immediately after his orders were received from Double Z.

It was in a dilapidated dive called the Green Mouse that Sneaks gained his hoped for results. While he was talking to a second-rate gunman, he noted a motion on the part of a man near by. Sneaks watched from the corner of his eye. Instead of turning toward him, the man turned away.

That might have been disarming, but for one fact. Sneaks Rubin had only seen the back of the man whom he had stunned in Bodine’s apartment. Now Sneaks recognized the same back at the near-by table! He had found his quarry!

Sneaks immediately became confidential in his tone, but he talked loud enough to his companion, so that the listening man might hear.

“Listen, Bud,” he said. “I’d like to find a torpedo as good as Clipper was. He was my — well, Clipper was a one-man mob in himself. I’m the guy that called him that—”

Cliff Marsland, listening, was elated. Sneaks had used the very term that he had heard Clipper use. The dead gangster had prided himself on being a “one-man mob.” Without doubt, Sneaks Rubin was the man who had arranged for Clipper Tobin to kill Arnold Bodine.

Sneaks was known to Cliff, although it was doubtful that the crafty little gangster knew Cliff by sight. The reason was plain. Sneaks was a character in the bad lands. Cliff was just a name.

Due to his long absence, Cliff was seldom recognized. Nevertheless, he decided to take no chances. He remained in his position, head turned away, until he saw Sneaks shamble from the place.

Cliff followed. He was cautious in his actions. He wanted to find out all he could by watching Sneaks.

Afterward, he could inquire regarding the pasty-faced crook whose name was so appropriate.

Now, Sneaks was bound for a definite destination, hopeful that Cliff would follow. He was going to confer with Double Z. Why not? In the back room of the dive he would be safe from observation. The action would mystify Cliff Marsland, and make him all the more willing to follow.

By a strange coincidence, it was the very time that Sneaks might expect a call from his mysterious chief.

Instructions, furthermore, would be valuable.

Sneaks had another purpose. When he shambled into his favorite hangout, he made a sign to a man who was lounging there. This sign was a familiar one at that place. It meant, “I’m being trailed. Watch who comes in!”

Then Sneaks entered the little back room, barred the door, and waited.

His call came, promptly at the appointed minute. One ring — if not answered, the phone would be hung up at the other end. Sneaks snatched up the receiver. He spoke hastily as he recognized the voice.

“The guy’s on my trail,” he said.

“Do you know who he is?” asked Double Z’s voice.

“No. I can find out—”

“Take him down to Loy Rook’s. Right away. That is most important.”

SNEAKS left the room. He saw a man sitting in the corner. The tip-off made a sign. Sneaks threw a sidelong glance and recognized Cliff’s appearance. He began to act furtively. He slipped out into the night.

His part was well played. Within two minutes, Cliff Marsland had left the dive and was scanning the sidewalks for the little gangster. He saw the stooping form of Sneaks Rubin in the distance.

Sneaks wandered cunningly. He gave no sign that he was being followed. He strode along through side streets, with the air of a man who has a definite objective. Cliff kept up the pursuit. It was not long before they reached the vicinity of the building where Loy Rook lived.

But on his journey, Sneaks had passed a lookout post where one of Jake Dermott’s vigilant men was always on watch. There, Sneaks had paused.

Standing in the light, the man had recognized him. So while Sneaks, slowly lessening his pace, reached Loy Rook’s neighborhood, the word had already reached Jake Dermott.

Sneaks turned into a back street. Here, on the fringe of Chinatown, Cliff Marsland was wondering. He knew that Harry Vincent was stationed at Loy Rook’s. Could that be where they were going?

The Shadow’s agents were kept well posted through the medium of Rutledge Mann. It was unlikely that Harry would expect Cliff; but Harry was always alert. Much might be gained tonight.

Cliff hoped that Sneaks would linger along the way, so that Cliff would have a chance to notify Burbank, The Shadow’s night sentinel. But had Cliff known where the trail might lead, he would have sent word before he had followed Sneaks into the second dive. It was too late now.

Sneaks stopped in a dark, narrow street. Cliff waited out of sight, behind a stack of barrels. He saw the little gangster make a motion beside a door. Then Sneaks disappeared.

Cliff advanced cautiously. He came to an open door, with a flight of steps ahead. He noted that the door was cleverly built so as to seem almost part of the wall.

Cliff hesitated. Should he leave temporary and call Burbank? He decided to go in. It was well that he did so, for unbeknown to him, the ends of the little street were already watched by Jake Dermott’s sentinels, ready to cut off his retreat!

CLIFF ascended the steps, automatic in his hand. He came to a hallway on the second floor. He stood there, in semidarkness. The only light came from a window at the end of the hall.

Cliff noted that he stood between two objects that looked like doors. A quick inspection proved that they were hinged bookcases. Cliff stepped forward in the dim light. He started quickly as he heard a low whisper.

“Cliff!”

His own name!

“Yes!” he whispered tensely.

“This is Harry — Harry Vincent.”

“Good. Is this Loy Rook’s?”

“Yes.”

“I’m trailing Sneaks Rubin.”

“A man just went upstairs.”

“I’m following, then!”

Cliff Marsland moved cautiously toward the third floor. Harry, in turn, slipped down the hallway. Silently, in the dark, he reached the office and dialed the telephone. Burbank responded. Harry quickly told him what was taking place.

During his residence with Loy Rook, Harry had made as many observations as possible. He knew that The Shadow was familiar with the situation here. Harry could see no danger to himself. He felt that he should forestall any possible trouble for Cliff Marsland.

The game was important. Still, it was Harry’s part to be cautious. He knew that Cliff could not possibly have notified Burbank of his whereabouts, so he had attended to that matter himself.

The hallway was empty when Harry reached his room. The bookcases were still open. That was a good sign.

With door ajar, Harry remained watchful within his room. His pocketed automatic was ready to be unlimbered at an instant’s notice.

At that particular moment, Cliff Marsland was also watchful.

He had reached the head of the stairs. He stood on the threshold of a dimly lighted room. It was an antechamber, furnished in Chinese style. A grinning joss rested beside the entrance. A paneled door showed between two curtains. That was evidently where Sneaks had gone!

What was happening behind that door?

The room seemed to have an alluring power. Try as he would, Cliff could not repress the urge to slip closer. This was increased by the sound of mumbled voices. The door was evidently a thin one, or the crack beneath it was by no means soundproof.

Cliff moved forward. He reached the door and crouched there. Even then, he could not make out words from the low conversation on the other side.

The room was a narrow one. It was also low-ceilinged. Cliff had walked forward about seven steps to reach the mysterious door. By spreading his arms, he could touch the wall on either side. After he had listened for several minutes, he chanced to move backward a trifle.

He bumped suddenly against something solid. He swung quickly, with his gun in hand.

Behind him was another door — a duplicate of the one in front. Silently, unnoticed, it had descended from the ceiling. He was in a boxlike trap, scarcely five feet square, not much over six feet in height!

Cliff clutched a curtain in front of him. His head was beginning to swim. That was odd! He tried to rise to his feet, but found it impossible. Dizziness swept over him. His throat was becoming numbed. Gasping, he sought to cry out, but an inarticulate gurgle was his only response.

Cliff sank to the floor, moaning. Some powerful gas was overwhelming him. If he could only signal to Harry! It was too late, now.

Cliff’s automatic slid from his nerveless fingers. He crumpled upon the floor. He fancied that he heard his name being whispered.

“Cliff! Cliff!”

He could not respond. He managed to give one last choking gasp. His final thought was the thought of death. Was this to be the end?

THE words that Cliff Marsland had heard had not been formed by his imagination. Harry Vincent, waiting below, had decided it was time to act. He knew that Cliff would return shortly, if only to post him regarding matters upstairs. So Harry, in turn, had ascended the narrow flight.

Like Cliff, he had encountered an antechamber with a curtained doorway at the end. But the space between Harry and the door that barred his path was only fifteen feet!

With Cliff Marsland, it had been twenty!

Harry, listening, also heard a sound beyond that doorway. It was a human utterance, but not in the form of words. Some one seemed to be gasping. Like a shot, Harry realized that Cliff had encountered trouble. He crept forward and stooped before the door, calling Cliff’s name in a low, tense whisper.

There was a faint response; but it could not be called an actual reply. Harry repeated his words. Silence was the only answer. What to do?

Perhaps it would be well to go downstairs; to enter the third floor by tapping at the entrance to Loy Rook’s door at the foot of the regular stairway. Harry would tell the old Chinaman that he had heard some one enter — that he had thought it best to inform his employer.

He turned as he raised himself to his feet. Like Cliff, he was startled. He was facing a blank door, within arm’s reach. He, too, was in a boxlike trap. He realized what had happened to Cliff Marsland. His friend was helpless; so was he!

Harry became unsteady. He felt a sickening sensation. It was doubly bad, for when he began to emit gasping cries, he knew that he was meeting the same power that had overcome Cliff. Was this a poison gas? Did every breath he drew spell doom?

He tried to hold his breath, but in vain. The odor of the gas was scarcely noticeable, but its effects were benumbing. Harry sank to the floor and tried to seek fresh air at the bottom of the door; but the barrier was tightly closed.

There was no hope. His senses were going. Despite the dim light that pervaded this weird prison, blackness was closing over Harry’s eyes. He gasped once, and lay inert.

Minutes went by — minutes that were unknown to the two victims, each in his own gas-filled prison. A figure appeared at the top of the stairway — a black-clad form that had arrived there in total silence.

A man, almost invisible in the darkness of the stairway, stood surveying the scene before him with eyes that were shaded beneath the broad brim of a slouch hat. About the newcomer’s shoulders lay the folds of a black cloak, as he stood close by the squat, hideous idol at the entrance.

The same antechamber lay in front of this man — the antechamber that ended with a curtained door. But the distance to the barrier was now but ten feet— not fifteen. The man in black stood silently, as though fascinated — as though about to move forward.

Two victims had fallen in Loy Rook’s toils — each in his separate trap. The third snare was in readiness — for The Shadow!