The absolute failure of Eldridge's hypothesis immediately threw public confidence into a profound reaction. Certainty gave place to complete distrust. Rumor gained ground. The exodus increased. Where formerly only those who could do so without great sacrifice or inconvenience had left town, now people were beginning to cut loose at any cost. Men resigned their positions in order to get their families away; others began to arrange their affairs as best they might, as though for a long vacation. As yet panic had not appeared openly in the light of day, but she lurked in the shadows of men's hearts.

The railroads and steamboats were crowded beyond their capacity. Extra trains followed one another as close together as the block signals would allow them to run. Humanity packed the cars. It was like a continual series of football days. In three of them it was estimated that two hundred thousand people had left Manhattan. It would have been physically impossible for the transportation lines to have carried a thousand more. They had reached their capacity; the spigot was wide open.

Percy Darrow showed Jack the head-lines to this effect.

"Cheerful thought," he suggested. "Suppose the whole four million should want to get out at the same time!"

Eldridge had come back to the wireless office thoroughly bewildered. It is a well-known fact that the exact scientist is the hardest man to fool, but the most fooled if fooled at all. Witness the extent to which noted scientists have been taken in by faking spiritualist mediums. So with Eldridge. His hypothesis had been so carefully worked out that the failure of its logic threw his mind into confusion. Until he could discover the weak link in his chain of reasoning, that confusion must continue.

An hour and a half after the bulletin announcing the failure of the search had been posted, Eldridge rushed into the wireless office. The plague of darkness had lifted after fifteen minutes' duration.

"Call Monsieur X," he gasped to the day operator. In fifteen minutes, by rapid substitutions of batteries to weaken or strengthen the sending current, he had redetermined his previous data. Apparently, without the shadow of a doubt, Monsieur X was within the circle.

"He may be at sea," suggested the operator.

But Eldridge shook his head. The circle of the sea had been well patrolled, and for days.

"Begin over again," drawled Darrow. "I told you that you were on the wrong track."

Eldridge glanced at him.

"I can't say that you've done much!" said he tartly.

"No?" queried Darrow, with one of his slow and exasperating smiles. "Perhaps not. But you'd better get to thinking. You won't be able always to take things easy. You may have to hustle before long."

"There has been, I admit," said Eldridge stiffly, repeating in substance the interview he had already given out, "some flaw in our chain of reasoning. This it will be necessary to review with the object of revision. Every physical manifestation must have some physical and definite cause; and this can be found if time enough is bestowed on it. Often the process of elimination is the only method by which the truth can be determined."

Darrow chuckled.

"Look out the process of elimination doesn't overtake you," he remarked.

Eldridge detailed the same reasoning, at greater length, to the men who had employed him. These were very impatient. Business was being not merely impeded, but destroyed. Their customers had no time for them; their employees were in many cases leaving their jobs. They called in all the help they could to assist Eldridge's speculations, but in the end they had to fall back on the scientist as the best on the market. The case was not left in his hands alone, however. After a meeting they offered a reward to any one discovering and putting to an end the disconcerting phenomena.

"Here's where we make money, Jack, big money," observed Darrow when he read this offer. "It'll be bigger before we get through. You and I can have the little expedition to Volcano Island."

"Nothing suits me better," said Jack. "Are you sure we'll get it?"

"Sure," said Darrow.

Monsieur X had of course honored the waiting world with a message. It followed the fifteen minutes of darkness:

"TO THE PEOPLE: I have been patient and have stayed my hand in order that you may learn the vanity of your endeavor. Who are ye that ye shall strive to take me? Vanity and foolishness is your portion. Now ye know my power and ye will listen unto my words as to the words of the Master. Ye must hunt down this man McCarthy and deliver him over unto me. If every one of you gives himself to the task, lo! it is quickly done. Bestir yourselves against the wrath to come!"

These events occupied the three days of the ordered exodus. The time was further filled with rumor that ever grew more dire. Gradually business was suspended entirely. Those who could not or would not go away stood about talking matters over, and, as is always the case, matters did not improve in the telling. The only activity in the city was that bent on seeking out the abiding-place of Monsieur X.

Eldridge had now come to the conclusion that he had perhaps been mistaken in confining his efforts to so small an area. In fact, further experiments rendered hazy the arbitrary outlines formerly determined for the zone of danger. At times Monsieur X answered well within the forty-five-mile mark; at times somewhat beyond the end of the fifty-mile radius. Eldridge immediately undertook a series of more delicate experiments by means of indicators especially designed by him for the occasion. Once more the little wireless office became the focus of repertorial attention.

"Our major premises we find still to be correct," announced Eldridge in the coldly didactic manner characteristic of the man. "This unknown operator is at a distance; and probably at a height. One indication we did not take sufficiently into consideration—the fact that this instrument alone is capable of communication with the instrument of this individual."

Percy Darrow for the first time began to show signs of attention. He dropped the legs of his chair to the floor and leaned forward.

"That would indicate, gentlemen, that the instrument whose location we are desirous of determining is of a peculiar nature. What that nature is we have no means of determining accurately; but in conjunction with the fact that our previous experiments failed to locate Monsieur X, we may adopt the hypothesis that the wireless apparatus of that individual is not so delicately responsive as the average. In other words, the zone within which he may be found is in fact wider than we had supposed."

Darrow leaned back against the wall and closed his eyes. Eldridge continued, explaining the means he had taken to determine more accurately the exact location of Monsieur X.