want no money. They are the first to try to get money when it is offered to them!'
'Maybe we can bait some of them!' said Burke bluntly.
The white-haired criminologist shrugged his shoulders. He seemed speculative for a few moments; then he spoke slowly and thoughtfully, making much of his words.
'We have to deal with a carefully deliberated crime,' he stated. 'Not the kind that springs from anger or from the quick impulse. It is the crime of the plotter, of the man that moves by stealth.
'Who is the man? Maybe I could tell you now. But I must have more time to think; I must not make a big mistake. It may not be just the one man - it may be two or three. But these will be the men who plan.
'Beneath them are the little men, those who have placed the bombs where they have exploded. You must find them, Herr Inspector. Have them for me!'
'You're right, professor,' interposed Burke. 'Joe Cardona will get the small fry. Leave it to him. But how long will it be before you haul in the big shots?'
'It shall not be long. I shall tell you this. It is not the time of which I am thinking. It is of explosions.'
'Just what do you mean by that?'
'There have been one - two - three - four,' replied Doctor Zerndorff, counting on the fingers of his left hand. 'Perhaps there shall be no more. Perhaps' - he pointed to the last outstretched finger - 'perhaps there shall be one more, yes?
'If that is so, I can promise you, there will be no more after that.'
'We don't want any more if we can help it!'
'Listen to me, Herr Inspector.' Zerndorff's voice was emphatic. 'My brain' - he tapped the fingertips of both hands against his forehead - 'my brain is understanding. I am like one who is in dreaming, yes?
'People I can see. Faces I can recognize; but I cannot grasp. Should they move once, I shall have them.
But I can only wait.
'Perhaps they shall not move. If they do not, my brain shall work of itself and I shall find them. You understand me, yes?'
'It's plain enough to me, chief,' said Cardona, tuning to Inspector Burke. 'The professor here knows what he is doing. I've been in the same fix myself. He's waiting to play his trump card. That's all.'
'I get you!' said the inspector. 'All right, professor, we're counting on you!'
Doctor Zerndorff rose and the other men followed. The three went downstairs together in the elevator.
On the ground floor, the professor placed his finger against his lips, and then spoke softly in the mellow light of the empty hallway.
'Up to now,' he said, 'these men have struck for just one thing - to frighten. Perhaps they shall try to scare again. I think so, yes.
'Perhaps you, Herr Detective, can discover them before they strike! A bomb - you may find somewhere.
But after that, they shall not try to scare. They will only protect themselves.
'They may fight, yes? If they do, who is the one they shall fight? The police? I say no! The police are too many.
'Here is the one' - he tapped his chest expressively. 'I am the one, yes; the one that they shall fight! They know that I know. You understand? There is danger, or there will be danger, here in New York, for me!'
'That sounds logical, chief,' observed Cardona, looking at Inspector Burke.
'So,' said Doctor Zerndorff quietly, 'do you think that I shall wait? No, no! It is for my own safety that I should see these men in prison.
'You may think of the public, Herr Inspector. That is good. I think, too, of the public - but,' he smiled, 'I think also of myself!'
He went to the outer door and carefully unbarred it. Standing in semidarkness, he peered across the street. An automobile lurked beside the opposite curb.
'See?' whispered Doctor Zerndorff. 'It may be now. I am suspicious. Friend or foe, I know not. So go, my friends, and remember that I shall solve this plot for you!'
Burke and Cardona stepped to the street. The door closed behind them. They heard the click of bolts.
The inspector coughed uneasily.
'Let's get the lay, Joe,' he said.
The two men walked boldly across the street. They saw two shadowy forms seated in the front seat of the sedan. Cardona's fingers sought the butt of his automatic.
'What're you doing here, buddies?' he asked.
Something sparkled on the breast of the man beside the wheel. In the reflected light of the street, Cardona recognized the badge of a secret-service agent.
'Hello, Cardona,' came a low voice. 'That's Inspector Burke with you, eh?'
'Right-o!' replied the detective.
'We watched you go in,' came the voice. 'We've been waiting for you to come out. We're detailed here to protect Doctor Zerndorff.'
Cardona was positive of the identity of the men. He looked at Burke and the inspector nodded his approval.
'We may have a police detail up here, later on,' said the detective.
'Okay,' came the voice from the car. 'Tell them we're here. We'll know them.'
Cardona hailed a passing taxi. He waved to the men in the sedan as he and Inspector Burke entered the cab. Then the street became silent. The secret-service men's automobile remained across the street.
The lights in the upstairs apartment went out, but the government men continued their vigil. In their keeping was the safety of the man in whose hands might lie the key to a nationwide plot of which the Manhattan explosions might be but forerunners.
A car going rapidly passed close by the parked automobile. The sharp eyes of the secret-service men were busy as they peered into the darkness of the passing coupe. It contained only the driver. One of the secret-service men sat up suddenly and nudged his companion.
'Did you hear that?' he exclaimed.
'No,' said the other, 'what was it?'
'It sounded like a low laugh - like a whispered laugh!'
The eyes of the watchers followed the taillight of the coupe until it disappeared in the distance. Then both men settled back to resume their vigil.
One - the man at the wheel - was calm and indifferent. The other was thoughtful and his mind was troubled.
For through his brain passed the haunting recollection of a sinister sound - a laugh so unreal that he could scarcely believe that his ears had not deceived him.
He felt confident that the coupe had come down that street for some special purpose; yet he could not imagine what its mission might have been.
The secret-service man was not acquainted with the underworld of New York. Had he known more, he might have understood. He would have attributed that laugh to more than fancy.
For that tone of sinister merriment had struck terror into the hearts of many gangsters. It was the laugh of The Shadow!
CHAPTER IV. THE HANDS OF THE SHADOW
INSPECTOR BURKE and Detective Cardona were sitting in the office at police headquarters. Outside, through the misty night, a clock boomed out the hour of eleven. The two men had just returned from their interview with Doctor Zerndorff.
Inspector Burke laid a sheet of paper on the desk in front of him. He began to write rapidly in pencil.
Cardona, watching him, knew what he was doing.
Burke possessed a photographic mind. Whenever the inspector held an important interview, he later wrote down the facts from memory. His task completed, Burke handed the sheet of notations to Cardona. The detective read it and nodded in admiration.
