IT was nearly an hour after the physician’s phone call when Detective Cardona reached the old house on Eighty-first Street. He did not enter the brownstone mansion immediately upon arrival. Instead, he stood across the street and uttered a low, almost indistinguishable whistle. Two men came from the darkness.

“Here’s the lay, boys,” whispered the detective. “I’m going in that house to see a man upstairs. There may be nothing to it, but I want you to hop in quick if you hear anything. How long have you been here?”

“Only about two minutes,” replied one of the men. “We put a couple of uniformed men out back, like you told us.”

“Good. Has any one gone in?”

“Not since we’ve been here.”

“All right. There’s no rush about it. If I come out first, be ready to grab the next fellow that comes out if I give the signal.

“If I want you inside, you’ll hear from me. If I don’t come out in thirty minutes, move into the house. If any guy enters, spot him, but don’t stop him. Savvy?”

“We got it.”

The detective sauntered across the street and silently entered the brownstone mansion. He found the front hall dimly lighted. He moved softly up the carpeted stairs.

Cardona remembered this house. He prided himself on the softness of his approach.

At the head of the stairs he saw the light thrown into the hallway from the open door of the room where Lukens expected a visitor.

There was a dark spot on the opposite side of the hallway. It offered an excellent observation place.

Cardona slipped to the location; there, crouching low, he turned to look into the silent room.

The desk was obscured from view. Cardona shifted to the side, risking a momentary chance in the light.

There the detective rested motionless, too astounded to take instant action.

Face down on the floor lay the body of a man! The bushy gray hair identified the person as Doctor George Lukens. The arms were outstretched, as though the dead man had made a despairing effort to throw himself upon an attacker. The fists were clenched; but there was something about the left hand that halted the detective’s gaze.

The third finger of that hand projected straight outward from the closed fist!

Beside the body was a living man, a figure clad in black. Enveloped in the folds of a huge cloak, this living person seemed like a specter of the night — a sinister being of another world, whose mammoth shadow lay across the body sprawled upon the floor.

CARDONA experienced a sensation mingled with fear and amazement. He recognized the being in black. It was one whom he had never encountered, yet whom he knew existed.

The detective realized that he was viewing a figure that had brought terror to the underworld; whose very existence was a mystery to the police and criminals alike. Cardona’s lips were dry as they phrased two words which the detective did not utter aloud.

“The Shadow!”

The demand for action surged through Cardona’s brain. The police had nothing on The Shadow. The mysterious man had been accused of crime, yet nothing had ever been proven against him.

On the contrary, he had — on occasions — helped the police in their war against crime, but always in his own mysterious way. He had never appeared in the light as a detective.

His purpose here tonight was a mystery to Cardona. That The Shadow was the visitor expected by Doctor Lukens the detective did not doubt.

Cardona, shrewd though he might be, was a man who jumped to immediate conclusions. Here was tangible evidence.

A dead man — Doctor George Lukens — who had been alive less than an hour before. Hovering over him was this monster of the night, the only person in the house. A dead man and a live man. The evidence lay against The Shadow.

Cardona had come to listen as a concealed observer. Now his purpose was to seize and capture a man whom he felt certain was a murderer.

The circumstances were pressing. Had his men been close by, Cardona would have proceeded cunningly. Had he felt that he was dealing with an ordinary criminal, he would have simply covered the man and demanded his surrender.

But he had heard too much of The Shadow. Now that the myth of the underworld had become reality, Cardona hesitated at halfway measures.

Death to the murderer was his only course!

The urge to observe what The Shadow was about to do restrained the detective momentarily, but he overcame the temporary hesitation. Drawing his automatic, Cardona straightened up and sprang into the room.

The sound of his approach made his presence known to the man in the black cloak. So promptly did The Shadow act that his motions seemed simultaneous with those of the detective.

Cardona’s arm, usually sure and firm, trembled slightly with excitement as his finger touched the trigger of the automatic. Then came a revolver shot; but not from the detective’s gun. From beneath his cloak, the man in black had whipped out an automatic.

Flinging himself full length on the floor to escape Cardona’s aim, The Shadow had fired from an angle.

The bullet struck the detective’s revolver just above the handle, grazing Cardona’s fingers. The damaged gun fell from the detective’s numbed hand.

As The Shadow started to rise, Cardona threw himself at the man in black. Angered, the detective forgot that he was at the mercy of his antagonist.

One shot from the automatic would have ended the detective’s plunge. But The Shadow did not fire.

Instead, he bent forward as Cardona fell upon him. As the detective’s bleeding hand grasped the black cloak, The Shadow lifted his shoulders and precipitated Cardona head foremost on the floor.

Cardona threw out an arm to protect himself and was partially successful, although he was half stunned by the force of his fall. As he tried to recover himself, he had a dazed view of a swiftly-moving form in black. The Shadow hurried from the room toward the stairs.

THERE was a loud clatter at the front door. The two plain-clothes men stationed by Cardona had rushed across the street at the sound of the shot.

The Shadow, standing at the head of the stairs, would have been a perfect target for their automatics; but they did not realize his presence until they had come halfway up the steps. Until he moved, he seemed nothing more than a blot of blackness against the wall.

With the approach of the plain clothes men, The Shadow turned and sprang down the hall. The cries of the men followed him. Revolvers were discharged wildly.

The Shadow stopped short, and his tall, black-clad form drew itself tensely against the wall. Two policemen were coming up the back stairs. That avenue of escape was cut off.

The detectives, shouting to the policemen, came running down the hall. They stopped in the gloomy darkness as the policemen met them. The four men had lost their quarry.

They were standing within a few feet of the doorway where The Shadow, calm and motionless, was waiting. Slowly, inch by inch, the door began to open inward, without the semblance of a sound. The Shadow was escaping from their midst!

While the four minions of the law were wondering, this incredible man of the night was leaving them. With iron nerve, he was moving with patient slowness, giving no sign that might betray his presence.

But for an unexpected incident, he would have made his secret exit.

It was Joe Cardona who unwittingly frustrated The Shadow’s escape. The detective, tottering unsteadily, came from the room into the hallway. He placed his hand against the wall and found a light switch. He remembered it from his previous visit to the house.

An instant later the hallway was flooded with light. A sharp cry came from one of the plain-clothes men.

There, plainly visible against the white background of the half-opened doorway, stood The Shadow!

A policeman acted promptly. As The Shadow twisted through the doorway, the man in uniform leaped upon him. The others followed before The Shadow could elude them. The Shadow gripped the doorway as the four men came down on him.

Cardona, suddenly restored to his senses, came down the hallway. He knew the formidable powers of the man whom the officers had captured. “Don’t let him get away!” he cried. “Shoot him!”

There was no chance to obey the last command. The captors were too closely gathered to risk a gun shot.

Then The Shadow became suddenly submissive. His automatic had been wrested from his hand, a plain-clothes man, frisking through the folds of the black cloak, brought forth another gun.

“I’ve got the rods,” the man exclaimed. “Hold him, boys.”

The policemen were pinning The Shadow’s arms against the wall. The plain clothes men stepped back as Cardona approached.

The detective did not waste an instant. He stepped up to The Shadow and reached for the broad-brimmed hat which had shifted forward so that it completely hid the face beneath the brim.

AT that instant The Shadow came to life. He swung his body toward one side with terrific force.

The policeman who held The Shadow’s right arm was flung against Cardona. The Shadow’s hand came free.

The plain-clothes men, coming in, were momentarily halted by the forms of Cardona and the officer. The other policeman still held The Shadow in a viselike grip, but he was no match for the man in black. With amazing strength, The Shadow lifted the man off the floor. Turning toward the doorway, he flung his foe against two new men who were entering.

Three quick strides and The Shadow’s black form was silhouetted against the window across the room.

It required several seconds for him to open the sash.

Shots rang out and glass was shattered. The Shadow’s form slumped, but it straightened quickly as the would-be captors came across the room in triumph.

With one sweeping motion The Shadow vaulted the low sill and dropped from the window, just as a hand plucked the folds of his black cloak. The Shadow slipped free of the garment, leaving it in the hands of his foe.

The plain-clothes man leaned from the window and aimed his automatic at the thin black figure on the ground below. Bullets ricocheted from the stone alley as The Shadow fled. The last shot whizzed above him and carried his hat from his head.

The Shadow swooped the hat from the ground as he turned the corner of the house. From the alley came the sound of a mocking, triumphant laugh.

Detective Cardona directed the pursuit. His men had not been badly injured in the fray. They hurried from the house by both doors in a mad effort to trace the man who had eluded them.

Cardona leaned against the wall beside the door of the back room. Then, picking up the black cloak which had been thrown on the floor, he walked slowly back to the room where the body of Doctor Lukens lay.

The detective found his automatic and laid it on the desk. He sat in a chair and stared at the physician’s body. He rubbed the side of his head and tried to ward off the dizziness that was overcoming him. He looked up.

Before him stood a tall, thin man clad in a close-fitting black suit. The man’s arms were folded. His head was bowed, and his face was shadowy beneath the brim of his hat.

STEADYING himself with one hand, Cardona reached for his automatic. The man in black laughed softly. He drew his cloak from Cardona’s knees. He wrapped the cloak about his shoulders and raised the collar high above his chin.

Cardona was examining his automatic. He saw the reason for The Shadow’s laugh. The gun was useless.

The Shadow’s shot had ruined it. The detective tried to rise from his chair, but sank back helplessly.

“Cardona,” said The Shadow in a low, weird whisper, “I am not your enemy. I did not kill Doctor Lukens. I came here to protect him. Do you understand?”

The detective nodded.

“Your men have captured my weapons,” continued The Shadow in that same strange voice. “You will find that the bullet that killed this man does not correspond to either of my automatics. The murderer left here before I arrived. He has taken the gun with him.”

Quietly The Shadow stooped over the body of the dead physician. He opened Lukens’s clenched right hand.

The pair of dice dropped upon the floor. They showed the number seven — a five spot and a two.

“There is a connection,” said The Shadow, rising. “Those dice were in Marchand’s desk. This murder — like Marchand’s death — has something to do with the number seven.

“Perhaps some fiend has planned seven murders. Perhaps” — his voice was thoughtful — “there are seven persons involved. Follow that clew. Seek the murderer.

“I shall tell you more. The gun was probably fitted with a silencer. That extended finger of Lukens’s left hand shows a purpose. The murderer desired a ring that he was wearing.

“Seek the murderer” — The Shadow’s voice was sibilant — “and I shall aid you. Premeditated murder, with Doctor Lukens taken unaware. I shall aid you. When I am certain of the murderer’s identity and have fathomed the plans of his associates, I shall reveal them to you.”

Cardona saw the flash of two burning eyes that peered from the depths below the broad-brimmed hat.

He clutched the arms of his chair to fight off dizziness. Then The Shadow was gone.

Outside, the two plain-clothes men were returning from their fruitless pursuit. They were startled by the sound of a long, taunting laugh that seemed to come from nowhere and that dwindled away to a mysterious nothingness.

It was the laugh of The Shadow!