THE town mansion of Peter Randolph was a big one. Situated on a side street not far from Riverside Drive, it stood in parklike grounds, surrounded by shrubbery and gardens. There was a walk in front, paved with ornamental Chinese brick. A board fence separated the grounds and house from the sidewalk.

The Randolph mansion was the last of its kind in the section. Millionaire neighbors of Randolph had sold their homes and had moved to Park Avenue. But not Randolph. He was a stubborn old man, ma.s.sive like the house he lived in.

Every winter he returned from his summer estate in Lakewood and brought Parker with him.

Parker was Peter Randolph's butler. The two lived alone in the old mansion. Randolph hated servants, particularly women servants. But he liked and trusted Parker.

On the same night that Lamont Cranston had been summoned to the home of Joe Cardona, Peter Randolph was seated alone in his library, reading the financial columns of the evening newspaper.

Suddenly, Randolph heard a peculiar sound. His face turned ashen with fear. The newspaper fluttered from his hands to the floor.

The sound that had startled him had come from Randolph's inner study. It was so low that he was not certain whether he had actually heard it or had merely imagined it. It was the m.u.f.fled echo of a dog's bark!

Randolph stepped to a cabinet and s.n.a.t.c.hed a pistol from a drawer. He was moving stealthily toward the door of his study when he halted abruptly.

Footsteps were audible outside, in the hallway of the mansion.

Peter Randolph hid the gun in his pocket. A moment later Parker, his butler, appeared. Parker was out of breath. His face looked queer.

"Are - are you quite all right?"

"Of course! What the devil do you mean?"

"I - I thought I heard you cry out," Parker gasped. "I thought something was wrong!"

Randolph's eyes flicked briefly toward the closed study door.

"I don't need you. You may go."

As Parker turned obediently away, the millionaire halted him for an instant.

"Was it a cry you thought you heard - or a bark?"

"A - a bark, sir?"

"Don't look so stupid! The noise a dog makes."

"No, sir. I heard no dog."

"It doesn't matter," Randolph said, faintly. "Go back to your quarters and don't bother me for the rest of the evening. I've got some important business papers to look over."

Parker backed out of the library, his well-trained face wooden. Peter Randolph whipped his gun from his pocket. He tiptoed to the closed door of his study. He waited rigidly for almost two minutes, listening. THERE was no further sound. Randolph threw open the door. His finger clicked on the lights. The study was empty.

Randolph drew a hissing breath of relief. He noted that the windows were all shut. The shades were neatly drawn, the same as he had left them. He advanced slowly toward a steel jewel vault that stood in a shadowy corner of the room.

Suddenly, he heard a cold chuckle of amus.e.m.e.nt.

He whirled. A man was standing in the center of the study, laughing at Peter Randolph. He was a tall, thin man, dressed entirely in gray. Gray suit and overcoat, gray spats, a trim gray derby. His gloved hands, also gray, were held peacefully outward in front of him. He had no weapon. Nor did he seem to be afraid of the gun in the trembling grip of the millionaire.

"Good evening, Mr. Randolph."

"Who are you?"

"David Frick is my name."

"How did you sneak in here?"

"That's my affair."

"If you make a single move, I'll kill you!" Randolph warned.

Frick laughed at the threat. He moved quietly toward a chair and sat down.

He took an expensive cigar from Randolph's ivory box and lighted it.

"I've come for the blood sapphire," he said, quietly. "Please let me have it."

Randolph uttered a choking sound.

"I - I don't know What you're talking about!"

"The stone I want is a large sapphire. It's not really a perfect sapphire, because in its center is a fleck of crimson like a smear of blood. You bought the stone secretly, because you knew it was stolen property. You paid five thousand dollars for it."

"How do you know all this?" Peter Randolph asked, hoa.r.s.ely.

"Perhaps I'm a detective," Frick sneered. "On the other hand, perhaps I'm a smart business man."

"Sorry. I'm not in the market, Mr. Frick. The sapphire is not for sale."

"I have no intention of buying it," Frick said smoothly. "I'm asking you to give it to me."

"And if I don't?"

Frick drew deeply on his cigar and exhaled a fragrant cloud of smoke.

"Perhaps I had better remind you of a few ugly facts. A little talk by me with Inspector Cardona will bring the police here with a search warrant. Or I might inform a certain Spanish gentleman named Senor Ortega. Does the name Ortega mean anything to you?"

Randolph's gun remained steady.

"Never heard of him."

"You should," Frick purred. "His real name is His Highness, Ali Singh. He is the Maharajah of Rajk.u.mana."

FEAR leaped into the eyes of the millionaire.

"So you see," Frick continued evenly, "you'd be very foolish to keep this sapphire. You're in danger from the vengeance of the Dog G.o.ddess of Rajk.u.mana, from whose nude golden body the Necklace of Purity was stolen."

"Did the Dog G.o.ddess hire you as a private detective?" Randolph sneered.

"Not at all! I hired myself. The stone I'm asking you to give me, plus others I shall obtain, will net me the pleasant profit of two million dollars.

And save you from a death that might be most horrible. Yes or no, Mr.

Randolph?"

"You're no detective. You're a crook - and you can go to h.e.l.l! The fact that I want no publicity is the only reason why you are escaping a bullet or a cell in jail. Get out the same sly way you sneaked in!" David Frick mashed out his cigar and rose to his feet.

"I'll leave by the front door, if you don't mind. And please don't ring for your butler."

There was a queer threat in the suave voice of the gray-clad David Frick.

Randolph made no effort to summon Parker. He merely kept the muzzle of his gun pointed at his visitor. Frick backed noiselessly toward the study door. The door opened quietly, then closed.

Randolph's glance strayed toward his jewel safe in the corner of the room.

Something about it seemed to rea.s.sure him. He laughed grimly, and poured himself a drink.

Opening a compartment in his desk, he began to examine a sheet of paper with a list of names typewritten on it. The fiery warmth of the whisky he had gulped down drove the chill from his heart. He lit a match and burned the paper to thin ash.

MEANWHILE, David Frick was gliding like a gray shadow through the quiet front hall of the mansion. No one stopped him. Parker, the butler, was somewhere in the rear. Frick opened the ma.s.sive front door and stepped to the darkness outside.

The moment he did so, he gasped with surprise. He flung himself flat on the stone threshold.

He had seen a parked automobile at the curb outside the low fence that closed off the property of the millionaire. A man was getting out of that car.

A man whom David Frick instantly recognized.

Frick's quick action in dropping flat had saved him from discovery. He bellied swiftly down Randolph's front steps. Then he melted across the dark lawn and lost himself in the shrubbery.

A moment later, the locked gate in Randolph's fence opened. A man darted into view. He glided stealthily up the ornamental brick walk and climbed the stone stoop. The light from the entry mansion fell across his grim features.

The man was Sam Baron.

He held a knife beneath his coat. It was the same weapon that had stabbed to death the unfortunate servant of Rodney Mason. Baron's left hand coolly pressed the bell b.u.t.ton.

There was a short wait, then the door opened. Parker stood on the threshold.

Sam Baron mumbled something in a low voice. Parker couldn't understand what was said, so he leaned forward.

Baron's left hand caught him by the throat. The savage grip choked off Parker's scream, and the next instant the victim was shoved backward into the vestibule. The knife plunged into Parker's chest.

The weapon was wielded by a killer who was a veteran with cold steel.

Parker slumped - dead on his feet. But he didn't fall. Sam Baron's grip held him upright.

Slowly, the vestibule door opened. Baron whistled softly. His whistle was echoed from the dark sidewalk; then a man slid inward to the grounds. He raced noiselessly to where Baron was holding the dead butler, his foot keeping the vestibule door from closing.

"Everything O.K., Squint?" Baron whispered.

"Yeah. Turk is all set with the car. n.o.body in sight."

"Swell! You know what to do with this dope?"

"d.a.m.ned right!"

"Squint's" powerful hands grabbed the dead butler, dragged him along the path to the gate. Soon, the smooth murmur of a powerful automobile engine began to recede. Sam Baron was back in the vestibule. Not a sound came from within the quiet mansion. Baron began to tiptoe down the hall toward the dimly lighted library. He knew that beyond the library was the study. Inside the study was Peter Randolph and a safe that contained a priceIess blood sapphire.

And no witnesses!

But Sam Baron was mistaken. There was a witness. Not inside the mansion, but outside. A crouched figure had seen the swift murder of Parker.

Hidden behind a black clump of shrubbery, the suave David Frick was grinning in the darkness. His grin was, if anything, more coldly murderous than the leer on Sam Baron's face.

CHAPTER IV.

THE MUTED BEAST.

THE knife was no longer in Baron's hand. He had wiped it clean on the butler's coat and replaced it in a scabbard beneath his armpit. His fingers were all he needed now.

He threw the study door suddenly open.

His surprise attack produced exactly the effect he had planned. Peter Randolph whirled in his chair, his jaw sagging with terror. Before he could utter a cry or clutch for the gun that lay on the desk beside him, Baron had bounded forward.

Fingers closed on the throat of the millionaire. Two murderous hands were methodically choking Peter Randolph to death.

The millionaire slid to the floor. He lay in a ghastly, twitching huddle beneath his killer. His crimson face turned slowly purple. But not for a second did the pressure of those deadly fingers relax.

When they finally let go, Peter Randolph was dead.

Gloves on Baron's powerful hands were stripped off with a swift double gesture. He wasted not a second of time. The sapphire he was after was in the big safe in the corner. He hurried toward the safe.

But suddenly, Baron halted. A queer, frightened look came over his swarthy features. He had heard a sound. Or rather, he had sensed sound in his brain.

He thought he had heard the dead man laugh!

Whirling, he stared at his victim. Randolph was stiff, motionless. Dead as a doornail! Chuckling uneasily, Baron again approached the safe in the corner.

Ordinarily, the crook would have knelt, pressed his ear to the metal, and manipulated the lock with the touch of bared, sensitive finger tips. But the uncanny feeling that he was in deadly peril persisted.

Baron examined every inch of the safe. Then he saw the holes.

There were six of them drilled in the top of the safe. They must have been drilled a long time ago. Their edges were as dusty and discolored as the metal itself. Baron sniffed like a suspicious animal.