Ricordo’s eyes were glassy. Now they opened wide.
On the verge of death, the gang lord forgot his wounds, forgot his enmity toward the police. All that he could sense was the tone of Joe Cardona’s words — cold utterances that sounded plainly amid the muffled murmur of the concourse.
LARRY RICORDO forgot the excited cries about him. He could hear only Cardona’s voice, repeating the same theme in steady demand:
“We were tipped off. We want to know just where the tip-off came from.”
“I’ll tell you where!” coughed Ricordo. “I’ll tell you where! It came from the guy in back of this game!”
In a spasm of dying fury, the gang leader had gained a tremendous hatred for the man who had betrayed him. Bewildering thoughts were racking Ricordo’s brain. Only one man could have played the traitor.
That man was Professor Folcroft Urlich.
Why not? The scientist had brutally disposed of Thomas Jocelyn. Similarly, he had decided to get rid of Larry Ricordo. To go out fighting — all because of a double-crosser! With failing strength, Ricordo gave the answer that Joe Cardona wanted.
“Urlich!” gasped the gang leader. “Professor — Folcroft Urlich! Place — on Long Island. Go — there. He — he is — the one—”
“He tipped us off?” questioned Cardona.
“He — he must have,” blurted Ricordo. “He — he told me to scram. Get him— out on Long Island — place called Philbrook—”
Cardona was nodding. He saw Larry Ricordo close his eyes. The gang leader gasped no longer. But his dying brain responded suddenly to a wild thought. A tremor shook Ricordo’s frame as he remembered the death trap which Urlich had prepared for all comers.
“Cardona” — Larry’s lips snarled as his eyes opened for the final effort. “Look out — when — you get — when — you get—”
The effort was too great. Ricordo’s twisted lips spat out a dying sigh. The gang leader’s body nearly rolled from Cardona’s grasp. The detective could feel it go limp. He knew that the final spasm had arrived. Larry Ricordo was dead!
Cardona let others hold the body. He arose to see Mayhew close beside him. Quickly, Cardona ordered the other detective to take charge of Ricordo’s removal. A dozen sleuths were here. Cardona growled orders.
Two minutes later, the ace detective was striding from the terminal with a squad of men at his heels. They piled into a waiting car, and Cardona gave the driver quick, tense orders. The car shot from the curb.
Shrieking along Lexington Avenue, it turned eastward toward a mammoth bridge that led to Long Island.
Detective Joe Cardona had worked speedily tonight. Less than an hour after Thomas Jocelyn’s death, he had received the tip-off concerning Larry Ricordo. Half an hour later, the gang lord had spoken before he died from Cardona’s shots. Half an hour from now, Cardona and his men would be at their new objective.
Joe Cardona was on the trail of silent death. He did not know that one had gone before him — that The Shadow was already at the spot where such death lurked.
The ace detective was pleased because he had forced those words from Larry Ricordo’s dying lips. He did not know that the gang lord had tried to give a warning also, but had failed!
Cardona and his men were heading for a fiendish trap. Soon they were to know the power of silent death that Folcroft Urlich wielded!
CHAPTER XXI. TUBES OF DOOM
IN Professor Urlich’s laboratory, a fiendish plan was nearing its completion. Cliff Marsland and Clyde Burke, still bound beside the wall, were watching preparations that they knew would mean their doom.
All the lights in use within the room had been concentrated on this side of the laboratory, which was near the front of the building. Sanoja and Rasch, the scientist’s willing servants, had fitted gleaming incandescents with reflectors so that a vivid glare pervaded this limited field.
Professor Urlich was seated in a folding armchair, with the air of a director in charge of a rehearsal. His orders, barked in foreign tongues that the attendants understood, had brought forth prompt obedience.
Yet the forthcoming experiment had required considerable time for preparation.
Cliff Marsland had ceased to feign grogginess. Clyde Burke, beside him, was also fully conscious.
Despite the cold terror which Professor Urlich’s presence caused, both of The Shadow’s agents were strangely fascinated by the details of the work which now seemed completed.
Directly in front of the two men stood a huge tripod, mounted on a circular base. This was a skeleton structure that ran on wheels, and its three legs gave it the grotesque appearance of a lonely gallows. At the top of the tripod were extended arms that supported a rim of metal.
This upper circle supported a huge carboy. The glass vessel, incased in wickerwork, gleamed with greenish hue. Its stopper, which had been inserted in place, was a glass plug from which extended two flexible pieces of shining hose.
As Sanoja pressed a little lever beside the rim that supported the carboy, the large container rocked slightly, showing that it was on a pivot that would enable it to be inverted. Sanoja readjusted the lever and the big vessel ceased to sway.
On either side of the central tripod stood a low skeleton base with upright rods that terminated in rings.
There were two of these, both large and massive.
Each pedestal held a container of thick glass, shaped like a mammoth test tube. Neither of the prisoners had ever before seen such tremendous cylinders of glass. The tubes were more than eight feet in height, and more than two feet in diameter.
As final preparation, Urlich’s men had brought forward two caps of metal large enough to fit over the large tubes. They had attached a hose to each cap. Professor Urlich cackled joyously as a signal that everything was ready.
CLIFF MARSLAND studied the face of the fiend. A demoniacal glee illuminated Urlich’s features. The scientist had watched the work of his servants with increasing interest.
In spite of that fact, Cliff had noticed that the professor never failed to note the three unlighted incandescents that projected above the spiral stairway at the center of the laboratory. Those bulbs were scarcely visible in the darkness beyond the concentrated illumination; but had one suddenly commenced to gleam, the professor would have spied it on the instant.
“We are ready, now,” remarked Professor Urlich, his eyes focused upon the silent prisoners. “Inasmuch as you are to be the subjects of my experiment, I shall explain its operation to you.”
He beckoned to Rasch, who appeared with a small tube that contained a tiny white mouse. The servant, a grin on his dull face, held the tube in the light. The prisoners noted that it was capped with a metal cover that had a round hole in the center.
Professor Urlich babbled in a foreign language. Sanoja passed a glass bottle to Rasch. The man held the tube in one hand, the bottle in the other, and poured a greenish fluid from bottle into tube.
A sizzling, smoky mixture manifested itself. The green was tinged with white and fumes slowly came from the hole in the cover. Slowly, the liquid cleared.
Simultaneous gasps of amazement came from Cliff and Clyde. The white mouse had vanished. The tube contained nothing but a watery fluid!
“It has always been my wish,” proceeded the professor, “to attempt this experiment on a larger scale. The greenish fluid which you observed — the same liquid which is in the large carboy — is virtually a universal solvent. It has no effect upon glass; but that is about the only substance which it does not dissolve with rapacious power.
“The pieces of hose which project from the carboy are my own invention — a flexible material which possess certain properties found in glass. It has been used to withstand the power of the solvent.