"You ask me when? It is now nearly eleven o'clock. They will go off at midnight. How? Ah, that is the clever part!
"Each bomb is fitted with a sensitive radio receiver. From a certain large broadcasting station, a gong is struck at the hour of midnight.
"You do not know which station? That is because the practice was started just one week ago. It is a weekly program that will be on tonight.
"My bombs are set to catch the note of that gong. Then they will explode!"
Zerndorff smiled and leaned back in his chair. The Shadow's automatic still threatened him. He knew that death was imminent.
But the man in the black cloak hesitated, hoping for one more statement from the man in whose hands lay the lives of hundreds of innocent victims.
"You are thinking of those who will die," remarked Zerndorff, The Black Master. "You think that you can save them. But wait! I have not told you of another bomb which I have set!
"This one is a time machine. It will explode at eleven o'clock, and while its victims will be few" — he chuckled — "very few, it will seal the fate of many, for it will render the midnight explosions inevitable!
"I have struck for vengeance! I brought death to Hubert Banks. I wanted death for Sforza and Pecherkin, for they were old enemies of mine. Like Banks, they shall die — despite that confession which you hold.
"For I have intended the explosion at eleven o'clock to prove that Heinrich Zerndorff was not concerned in these crimes — to make him seem to be an intended victim.
"I was to leave here at ten minutes of eleven. I have changed my plan. It is now one quarter-minute before the hour. I see the clock on the wall behind you, Shadow.
"The bomb is in this room! It will blow me to eternity — and you will die with me! You cannot escape — there are but five seconds left!"
For one short instant, The Shadow did not move. In that moment, his brain responded.
He was well within the room. The doorway was twenty feet away. The door was closed and The Shadow had locked it! In his path sat The Black Master, ready to spring for a death struggle despite the leveled automatic — ready to spring at any instant when the slightest delay meant death!
Beyond the door was the path to safety, but it was too far away!
While Zerndorff's gloating eyes still watched him, The Shadow turned. Behind him was a vaulted doorway that stood before a closetlike alcove.
Into that space The Shadow sprang, and as he huddled his body toward the floor, he turned his back on the room of doom. A terrific explosion followed.
The bomb had been placed beneath the flooring, where Zerndorff was sitting. The walls of the building were shattered by a tremendous blast.
Down into empty space fell the entire room, a shattered mass of debris — and with it fell the dead form of The Black Master!
Police gongs clanged. Patrols and fire trucks were rushing to the mass of wreckage. All that remained of Zerndorff's apartment was a huge pile of shattered masonry and woodwork.
Firemen were tugging at beams and burrowing through piles of loose stones in an attempt to rescue any who might be buried alive. For twenty minutes their frenzied labors were in vain. Then they came upon the top portion of a wooden archway.
As they dislodged a few loose bricks, a voice spoke weakly from beneath the wooden frame. With skillful efforts, the firemen cleared a space. The form of a man came into view.
He was lying on his side, his hands pressed against the framework with which he had fallen. The arch had turned aside the avalanche of debris that had poured from above.
The man's body was covered with a black cloak; a huge hat was forced down over his eyes. Strong arms gripped him and pulled him carefully through the narrow opening. Two firemen caught him beneath the arms and half carried him to a waiting ambulance.
The vehicle was clanging down the street as soon as he was placed aboard.
It stopped within a block, its path obstructed by a fire truck. The instant it halted, the man in black flung aside the interns who were starting to examine him for injuries.
Free of their grasp, he leaped to the street and staggered off through the crowd. The ambulance began to move before the startled interns could pursue their charge. They caught one last fleeting glimpse of him; then he was swallowed amid the gathered throngs.
CHAPTER XXIII. A SECOND TO SPARE
A man came into the lobby of an uptown hotel. He faltered as he walked, and he made a strange figure.
He was clad in a long black cloak. His head was bent forward and his face could not be seen beneath his hat. His dark garments were streaked with dashes of light-colored dust.
There were but few persons in the lobby. They looked curiously at the man as he went into a telephone booth.
A few minutes later, the man was speaking over the telephone. His voice was weak and his words were almost inaudible.
"Burbank," he said.
He waited for a reply.
"Emergency radio," he continued. "Immediately!"
The black-clad form seemed to collapse within the booth. It sagged helplessly for a time; then straightened. Once again The Shadow was calling a number.
"Cardona?" came his weak voice. "No? Then Inspector Burke? I must speak to him!"
"Hello, inspector. Explosion at Zerndorff's. No, I cannot tell you who is speaking. Listen — it is only the first. Act quickly!"
"Manhattan Bridge; a bomb there, somewhere — Holland Tunnel, another bomb — New Gotham Hospital, a bomb hidden there. That is all—" The voice trailed away.
There was a long silence while a huddled form lay almost invisible within the booth. Then the weary figure came to life again.
The man walked unsteadily through the lobby and out into the street. As he passed the clock above the doorway, the hands were nearing twelve o'clock.
At that moment, radio broadcasting in the entire East was encountering a sudden problem. Signals had been picked up, apparently some miles off the coast of Massachusetts. A ship at sea was signaling its distress.
A program was nearing its end at Station WKR, in New York. The end of a dramatic sketch was close at hand. Only five minutes remained.
A young man was sitting near the microphone, holding a gong in one hand, a padded stick in the other.
He was awaiting the end of the program, to strike the single gong that marked its conclusion.
A man hurried into the studio. He thrust a note into the hand of the announcer, who glanced at it quickly.
The announcer motioned the players to stop their dialogue. They obeyed.
The announcer spoke. He stated that due to S-O-S signals from a sinking ship, the program would not be completed.
As the announcer finished his statement, the young man near the microphone grinned and raised the padded stick. He held it for an instant; then struck it against the gong.
Just as the padding neared the metal, a hand pulled the switch in the control room. Station WKR was off the air!
The next afternoon, Clyde Burke was busy in his clipping office. This young man was an ex-reporter.
Secretly, he was an aide of The Shadow.
To date, his part had been a passive one. He knew nothing of The Black Master. He was puzzled by the clipping that he laid before him.
The explosion at Doctor Zerndorff's, with the resulting death of the famous criminologist, was important news. But it was not the main sensation.
During the night, the police, acting on a mysterious tip, had discovered three huge bombs, after an extensive search. One had been found beneath a pier of the Manhattan Bridge; another in the Holland Tunnel; the third in a locker room of the New Gotham Hospital.