Cardona saw Ungler go in an opposite direction. Evidently, Ungler had suggested that he remain here a while and check the details of other gems that were on display. Part of the secretary's business was to list items that Berkland, as a gem collector, might wish to buy.

Officials of the exposition had surrounded Commissioner Weston. They were anxious to show other attractions to the commissioner. Cardona remained alone behind the end ropes. Deep in thought, Joe stared toward the steel case that contained the Seven Drops of Blood. The glint of the rubies seemed to tantalize him, as if the stones knew and could tell the ident.i.ty of the master criminal who once had held them.

Fine, invisible spray must have bathed the gems, for Cardona saw the gla.s.s cloud above them. That, too, was typical of the mystery that had covered the actions of the master crook. Cardona saw the mist clear; he hoped that the same would be true to the hunt that lay ahead of him.

An instant later, Cardona's reflections ceased.

A change was coming over the Seven Drops of Blood!

THE rubies were no longer rounded. They had elongated; they were flattening. Leaning forward, his eyes unbelieving, Cardona saw the change continue. He could hear the loud, excited buzz of other witnesses, as they watched the uncanny contortions of the gems.

A glisten replaced the sparkle of the rubies. They looked like beads of thick glycerine, tinged crimson. They widened farther; spread like miniature hotcakes. The rubies were melting under Cardona's eyes!

Another spray; a trifling cloud upon the gla.s.s. When the heat ended the haze, the transformation was complete. The steel case and its photoelectric beams had become a travesty. Uselessly, those protective devices were guarding a chest that contained no treasure.

Solid no longer, the supposed rubies had become completely liquid. Spread like blobs upon a windowpane, they bore no resemblance whatever to the precious stones that they had represented. Despite the examination of experts and the tests that had been made, those ruddy beads had been false.

Splotched objects on their ornamental plaque, the melted stones were worthless. But their new appearance exactly fulfilled the term by which they had been t.i.tled.

Seven Drops of Blood!

CHAPTER XX.

CARDONA'S LUCK.

IN the tense seconds that followed, a mult.i.tude of thoughts flooded Joe Cardona's brain. Though given to hunches, Cardona was not imaginary; nevertheless, the first conjecture that struck him was that some amazing thing had happened. He actually believed, for a moment, that an incredible force had been used to penetrate the bulletproof barrier and dissolve the rubies.

His thoughts flashed instantly to the Hindu, Rahman Singh, as if that visitor from the East possessed an eye of evil that could have delivered the malefactions of a dead maharajah. That thought ended. Cardona forgot the Hindu; he pushed out through the crowd to look for others. Ungler might be nearer; Cardona remembered that the secretary had gone to look at other jewels. But Ungler had evidently stepped outside first. Cardona saw no sign of the secretary. Excitement was starting in the room. As guards hurried to learn the trouble, Cardona hastened outside.

Woolford had said that he intended to remain and view the exposition; but Cardona could not spy him. That was not surprising. Thousands of people were present; and more were coming.

Cardona needed someone to question. He thought of Mogridge, and remembered that the mustached man had left some time before and was probably gone. The last bet was Berkland. Cardona knew where to find him and tell him the news.

Berkland had gone to his home.

There were telephone booths on the ground floor. Cardona entered one and called Berkland's home. There was no response. Perhaps the oil magnate had not yet arrived there.

Cardona decided to make a quick trip to Berkland's house. It was better than staying here. Nothing could be gained by contacting Commissioner Weston.

As for Ungler and Woolford, Cardona was convinced that one or the other would be gone. The one who was missing would be the one he wanted.

By going to Berkland's, Cardona might be able to gain some thread of evidence. Perhaps Berkland could supply a lucky one.

With that thought in mind, Cardona tried to board a taxicab outside the exposition building. A big doorman stopped him. Cardona flashed a badge. The doorman's manner changed.

"Sorry, inspector," he apologized. "We've been having trouble with the crowd. They bunched around one taxi, because they saw a Hindu getting into it -".

"The Hindu!" interrupted Cardona. "Where did he go?"

The doorman stood with his hand on the doork.n.o.b of a taxi. He was trying to recall an address.

"He went to some apartment house," he said. "I can't remember the address, but he gave a name, too. The place was called the Glas...o...b..ry -"

"Maybe the driver knows the place."

WITH that remark, Cardona boarded the cab and started south on Lexington Avenue. He quizzed the hackie; the fellow nodded and gave an address, which he was sure was the Glas...o...b..ry. He had taken pa.s.sengers there before.

When Cardona's cab reached the address, the driver proved to be right.

Cardona hurried into the Glas...o...b..ry Apartments, to find a dull-faced operator in an elevator. Cardona questioned about the Hindu. The operator stood stupidly for a few moments, then nodded.

"Guess that was him, all right," he said, "but he didn't have no turban.

I.

remember him, though, 'count of him being sorta dark. He went up to the penthouse."

"Who lives there?"

"I don't know. There's a guy goes up once in a while, but I never took a good look at him. I just got the job here a few weeks ago. I don't know many of the people yet."

"Take me up to the penthouse."

The operator hesitated. Cardona flashed his badge. The fellow gawked and nodded. The elevator started a speedy upward trip, with Cardona aboard. All the way up, Cardona was congratulating himself upon his luck. If any one couldreveal some peculiarity inherent to the rubies that had made them melt, Rahman Singh should be that man.

At the penthouse level, Cardona stepped into an entry. He opened a door ahead, looked in to see Rahman Singh standing by a window, studying the lights of Manhattan. The Hindu was oblivious to Cardona's arrival.

Joe motioned to the elevator operator, signaling that he could go down to the ground floor. Before the fellow could clang the big doors, Cardona stepped into the living room where Rahman Singh stood. Joe closed the door behind him.

Rahman Singh turned; he studied the arrival, then bowed politely. He looked puzzled, as though he had expected someone else to enter. When Cardona flashed his badge, Rahman Singh eyed it quizzically. He gave a musical laugh and nodded his recollection.

Ah, yes," he remarked. "I saw you when I was introduced to the police commissioner. Why have you come here, inspector?"

Cardona had already decided to be cagey. He preferred to ask a few questions before mentioning the fate that had overtaken the rubies. Joe put the first one.

"You have an appointment here," he announced. "Who is it with?"

"I am sorry," rejoined Rahman Singh, politely. "I have agreed to mention it to no one.

"I represent the law," reminded Cardona, grimly. "You'll be in a bad spot, Mr. Singh, if you hold out information. Anyway, I'm staying here until the fellow shows up."

Rahman Singh looked troubled. His eyes became restless. Cardona followed his changing gaze; noted for the first time how small the penthouse was. It seemed to consist only of this living room. The wall beyond was solid.

"Very well," decided Rahman Singh. "I presume that it is my duty to answer your question. The name of the man who arranged for me to meet him here is -"

THE Hindu stopped. Cardona spun about, noting a change of the man's gaze.

Facing the entry door, Cardona saw another man who had just arrived by elevator. A revolver in his fist, the newcomer held Joe covered. Above the gun were hard eyes, peering from a face that Cardona instantly recognized.

The man on the threshold was Glen Mogridge.

It took no mind-reading ability for Cardona to know that he faced the master criminal. Mogridge's glare, his ugly challenge, the very fact that he had arranged this secret meeting - all were proof that Berkland's brother-in-law had engineered the game.

Approaching with long stride, Mogridge pressed his revolver close to Cardona's chest. With his free hand, he found Joe's gun and yanked it from its pocket. With a nudge he pushed Cardona to a chair.

Keeping him covered, Mogridge produced a chamois bag and handed it to Rahman Singh. The Hindu opened the bag eagerly. Cardona stared, as he saw round, red pellets glisten in a falling trickle.

They were rubies! The gems that Mogridge had pa.s.sed to Rahman Singh were the Seven Drops of Blood!

Rahman Singh examined the rubies carefully beneath a strong lamp. He poured them back into the bag, then bowed to Mogridge.

"These are the Seven Drops of Blood," declared the Hindu. "Our transaction is complete. The promised funds await your arrival in England. Mr. Mogridge, I have pledged the word of Rahman Singh."

Solemnly, the Hindu turned to leave. Cardona saw the pleased leer that dominated Mogridge's mustached face. Though Cardona could not understand the strange reappearance of the rubies, he recognized one certain fact. His own life would be ended by Mogridge - as soon as Rahman Singh was gone. Again, Cardona looked hastily about the room - this time, hopeful for a route of escape. He saw no opportunity for exit. The walls, adorned with tapestries and paintings, formed a solid line, except for windows that were equipped with gratings. Mogridge blocked the way to the entry door, the way by which Rahman Singh intended to go.

CARDONA shot a quick glance toward the Hindu. Rahman Singh paused. His eyes showed pity; but his manner was firm. He intended to leave Cardona to his fate. Nevertheless, through courtesy, Rahman Singh decided to explain his action.

"In my land," said Rahman Singh, "we have a tradition which has long persisted. We believe that the Seven Drops of Blood bring death to those who are not their rightful owners. We also believe that the rubies are ours. Many years ago, they were taken from Bolopore. We have since tried to reclaim them.

"We were willing to pay the required price. That fact became known to Mr.

Mogridge. He agreed to deliver the rubies. In return, the present Maharajah of Bolopore agreed to pay one million dollars; but he insisted that nothing be done that would lead to international complications."

Rahman Singh paused. Mogridge, gloating, decided to add some remarks for Cardona's benefit.

"Sounded like a long order, didn't it?" jeered the gem thief. "I figured how to handle it, though. I found an old professor who could turn out synthetic rubies. Perfect matches for the Drops of Blood. All he had to do was copy them.

He did it in one process; and I gave the phony rubies - six of them - to the crowd who helped me."

Cardona looked to Rahman Singh.

"You let him do that?" growled Joe. "Let Mogridge get away with murder, so you could buy the real rubies?"

"I regret all that has occurred." Rahman Singh's apology was sincere. "We of the East, however, do not judge matters by your standards. Mr. Mogridge has complied with our terms."

"But the fake rubies will make trouble for you -"

"Not at all," interposed Rahman Singh, blandly. "They will continue to pa.s.s as the Seven Drops of Blood. They have stood all tests. I, myself, have observed them. No one will ever know that they are subst.i.tutes."

Instantly, Cardona saw opportunity. Forgetting Mogridge, he rose halfway from his chair and exclaimed to Rahman Singh: "You're wrong! Those rubies are known to be fakes! They're melted and I know now what made them. They were taking two tests at once - the heat and the moisture; that's what finished them. You call them Drops of Blood. That's what they look like - big gobs of blood, inside that steel exhibit box."

MOGRIDGE thrust Cardona back in his chair and snarled words to Rahman Singh.

"Don't let him bluff you," insisted Mogridge. "Handling this fellow is my business, Rahman Singh."

The Hindu hesitated; at last he bowed, as though convinced by Mogridge's words. Cardona made a last effort to gain Rahman Singh's cooperation. His life hung on whatever aid the Hindu might offer.

"What do you think brought me here?" demanded Cardona. "Can't you see that something happened down at the exposition? Call up the place from here. Find out for yourself what happened to the fake rubies."

"It's a stall," a.s.sured Mogridge. "Cardona took a chance on followingyou, that's all, Rahman Singh. He deserves what he's due to get. Remember our agreement."

Rahman Singh showed doubt. Cardona's words had impressed him. Mogridge saw it. He wanted the deal closed, so that he could dispose of Cardona. Mogridge did not believe Cardona's statements.

"I'll prove it to you, Rahman Singh," decided Mogridge, suddenly. "I'll show you how synthetic gems can stand both tests at once. Right here in my own laboratory."

Keeping Cardona covered, Mogridge stepped to a tapestry. He pressed a hidden spring; a frame swung outward from the wall, showing a blackened pa.s.sage beyond it. Moving toward Cardona, Mogridge snapped an order: "You go ahead. I'll follow with Rahman Singh."

Cardona was staring at the Hindu. He saw Rahman Singh stiffen, his eyes fixed on the opening in the wall. Mogridge saw Cardona's gaze and the reason for it. A strange whisper reached his ears. Mogridge whipped about. He came to a halt, his gun hand lowered, as the whisper rose to a chilling tone of mirth.

A figure had stepped from blackness, straight into the room. Mogridge was covered by a leveled automatic, held by a being whom he had met before. The Shadow, after listening to all that had pa.s.sed, had stepped from the depths of Mogridge's own lair to trap the master crook.

Joe Cardona's luck had not ended. Once again, The Shadow had come to his aid.

CHAPTER XXI.

THE SETTLEMENT.

GLEN MOGRIDGE stood helpless as he faced The Shadow. Gawking, the master murderer had lost the ease and confidence that he had held until this moment.

He realized that The Shadow had ferreted his schemes in full. Proof of that was given when The Shadow spoke accusing words.

"Your hand was shown early, Mogridge," p.r.o.nounced The Shadow, "even though the proof was not final. You, alone, would have been bold enough to enter Pettigrew's before the auction; there to overpower a watching detective. To gain entry, you needed an admittance card. You had one.

"You left the auction room. But Pettigrew and his a.s.sistant had seen you there. That was why you murdered them. Cleverly, you took the box that had the invitation cards. Thus you had your original card afterward. Woolford had no card. True, there was a blank guest card at Berkland's; but if Woolford had taken it, he would have had no opportunity to replace it.

"As for Ungler, he showed forgetfulness regarding that card. That was an unlikely pose for any criminal. Ungler would either have produced the card promptly, or he would have destroyed it earlier, so that the law would think it stolen by the person who cut the telephone wires."

The Shadow paused. The sourness of Mogridge's face showed the gem killer's chagrin. Suddenly, Mogridge began a snarled statement. The Shadow's whispered tone cut him short.

"You arrived at Pettigrew's soon after the crooks had fled," announced The Shadow. "Too soon, the law believed, for you to have transferred from a fleeingcar to a taxicab. The law was right on that point; but the law overlooked a possibility. It did not occur to the police that one of the cars in the rear garage could have been a taxicab.

"That was the car you took, Mogridge, with one of your henchmen at the wheel. You rounded the block and arrived at Pettigrew's front door immediately.

Your taxi was allowed to go its way. Later, you proved your weakness for cabs.

You used one after you murdered Twitcher Killick. Your henchmen used cabs when they tried to ambush Rund."