Part 21

Bill arose lazily, and The Thinking Machine sank down into the chair. From this point he could see plainly through the opening into the basement proper--there was no door--the gas meter of enormous proportions through which all the gas in the house passed. An electric light in the door made it bright as daylight. The Thinking Machine noted these things, arose, nodded his thanks to the two men and, still with the puzzled expression on his face, led the way upstairs. There the manager was still in his office.

"I presume you examine and know that the time check in the engineer's room is properly punched every half-hour during the night?" he asked.

"Yes. I examine the dial every day--have them here, in fact, each with the date on it."

"May I see them?"

Now the manager was puzzled. He produced the cards, one for each day, and for half an hour The Thinking Machine studied them minutely. At the end of that time, when he arose and Hatch looked at him inquiringly, he saw still the perplexed expression.

After urgent solicitation, the manager admitted them to the apartments of Weldon Henley. Mr. Henley himself had gone to his office in State Street. Here The Thinking Machine did several things which aroused the curiosity of the manager, one of which was to minutely study the gas jets. Then The Thinking Machine opened one of the front windows and glanced out into the street. Below fifteen feet was the sidewalk; above was the solid front of the building, broken only by a flagpole which, properly roped, extended from the hall window of the next floor above out over the sidewalk a distance of twelve feet or so.

"Ever use that flagpole?" he asked the manager.

"Rarely," said the manager. "On holidays sometimes--Fourth of July and such times. We have a big flag for it."

From the apartments The Thinking Machine led the way to the hall, up the stairs and to the flagpole. Leaning out of this window, he looked down toward the window of the apartments he had just left. Then he inspected the rope of the flagpole, drawing it through his slender hands slowly and carefully. At last he picked off a slender thread of scarlet and examined it.

"Ah," he exclaimed. Then to Hatch: "Let's go, Mr. Hatch. Thank you," this last to the manager, who had been a puzzled witness.

Once on the street, side by side with The Thinking Machine, Hatch was bursting with questions, but he didn't ask them. He knew it would be useless. At last The Thinking Machine broke the silence.

"That girl, Miss Regnier, was murdered," he said suddenly, positively. "There have been four attempts to murder Henley."

"How?" asked Hatch, startled.

"By a scheme so simple that neither you nor I nor the police have ever heard of it being employed," was the astonishing reply. "It is perfectly horrible in its simplicity."

"What was it?" Hatch insisted, eagerly.

"It would be futile to discuss that now," was the rejoinder. "There has been murder. We know how. Now the question is--who? What person would have a motive to kill Henley?"

III.

There was a pause as they walked on.

"Where are we going?" asked Hatch finally.

"Come up to my place and let's consider this matter a bit further," replied The Thinking Machine.

Not another word was spoken by either until half an hour later, in the small laboratory. For a long time the scientist was thoughtful--deeply thoughtful. Once he took down a volume from a shelf and Hatch glanced at the title. It was "Gases: Their Properties." After awhile he returned this to the shelf and took down another, on which the reporter caught the title, "Anatomy."

"Now, Mr. Hatch," said The Thinking Machine in his perpetually crabbed voice, "we have a most remarkable riddle. It gains this remarkable aspect from its very simplicity. It is not, however, necessary to go into that now. I will make it clear to you when we know the motives.

"As a general rule, the greatest crimes never come to light because the greatest criminals, their perpetrators, are too clever to be caught. Here we have what I might call a great crime committed with a subtle simplicity that is wholly disarming, and a greater crime even than this was planned. This was to murder Weldon Henley. The first thing for you to do is to see Mr. Henley and warn him of his danger. Asphyxiation will not be attempted again, but there is a possibility of poison, a pistol shot, a knife, anything almost. As a matter of fact, he is in great peril.

"Superficially, the death of Miss Regnier, the maid, looks to be suicide. Instead it is the fruition of a plan which has been tried time and again against Henley. There is a possibility that Miss Regnier was not an intentional victim of the plot, but the fact remains that she was murdered. Why? Find the motive for the plot to murder Mr. Henley and you will know why."

The Thinking Machine reached over to the shelf, took a book, looked at it a moment, then went on:

"The first question to determine positively is: Who hated Weldon Henley sufficiently to desire his death? You say he is a successful man in the Street. Therefore there is a possibility that some enemy there is at the bottom of the affair, yet it seems hardly probable. If by his operations Mr. Henley ever happened to wreck another man's fortune find this man and find out all about him. He may be the man. There will be innumerable questions arising from this line of inquiry to a man of your resources. Leave none of them unanswered.

"On the other hand there is Henley's love affair. Had he a rival who might desire his death? Had he any rival? If so, find out all about him. He may be the man who planned all this. Here, too, there will be questions arising which demand answers. Answer them--all of them--fully and clearly before you see me again.

"Was Henley ever a party to a liaison of any kind? Find that out, too. A vengeful woman or a discarded sweetheart of a vengeful woman, you know, will go to any extreme. The rumor of his engagement to Miss--Miss----"