"Here, I believe, is the real clew to the problem," he explained to Hatch. "What does it seem to be?"
Hatch examined it closely.
"I should say a strand from a Turkish bath robe," was his final judgement.
"Possibly. Ask some cloth expert what he makes of it, then if it sounds promising look into it. Find out if by any possibility it can be any part of any garment worn by any person in the apartment house."
"But it's so slight--" Hatch began.
"I know," the other interrupted, tartly. "It's slight, but I believe it is a part of the wearing apparel of the person, man or woman, who has four times attempted to kill Mr. Henley and who did kill the girl. Therefore, it is important."
Hatch looked at him quickly.
"Well, how-in what manner-did it come where you found it?"
"Simple enough," said the scientist. "It is a wonder that there were not more pieces of it-that's all."
Perplexed by his instructions. But confident of results, Hatch left The Thinking Machine. What possible connection could this tiny bit of scarlet thread, found on a flagpole, have with one shutting off the gas in Henley's rooms? How did anyone go into Henley's rooms to shut off the gas? How was it Miss Regnier was dead? What was the manner of her death?
A cloth expert in a great department store turned his knowledge on the tiny bit of scarlet for the illumination of Hatch, but he could go no further than to say that it seemed to be part of a Turkish bath robe.
"Man or woman's?" asked Hatch.
"The material from which bath robes are made is the same for both men and women," was the reply. "I can say nothing else. Of course there's not enough of it to even guess at the pattern of the robe."
Then Hatch went to the financial district and was ushered into the office of Weldon Henley, a slender, handsome man of thirty-two or three years, pallid of face and nervous in manner. He still showed the effect of the gas poisoning, and there was even a trace of a furtive fear-fear of something, he himself didn't know what-in his actions.
Henley talked freely to the newspaper man of certain things, but of other things he was resentfully reticent. He admitted his engagement to Miss Lipscomb, and finally even admitted that Miss Lipscomb's hand had been sought by another man, Regnault Cabell, formerly of Virginia.
"Could you give me his address?" asked Hatch.
"He lives in the same apartment house with me-two floors above," was the reply.
Hatch was startled; startled more than he would have cared to admit.
"Are you on friendly terms with him?" he asked.
"Certainly," said Henley. "I won't say anything further about this matter. It would be unwise for obvious reasons."
"I suppose you consider that this turning on of the gas was an attempt on your life?"
"I can't suppose anything else."
Hatch studied the pallid face closely as he asked the next question.
"Do you know Miss Regnier was found dead to-day?"
"Dead?" exclaimed the other, and he arose. "Who-what-who is she?"
It seemed a distinct effort for him to regain control of himself.
The reporter detailed then the circumstances of the finding of the girl's body, and the broker listened without comment. From that time forward all the reporter's questions were either parried or else met with a flat refusal to answer. Finally Hatch repeated to him the warning which he had from The Thinking Machine, and feeling that he had accomplished little, went away.
At eight o'clock that night-a night of complete darkness-Henley was found unconscious, lying in a little used walk in the Common. There was a bullet hole through his left shoulder, and he was bleeding profusely. He was removed to the hospital, where he regained consciousness for just a moment.
"Who shot you?" he was asked.
"None of your business," he replied, and lapsed into unconsciousness.
IV.
Entirely unaware of this latest attempt on the life of the broker, Hutchinson Hatch steadily pursued his investigations. They finally led him to an intimate friend of Regnault Cabell. The young Southerner had apartments on the fourth floor of the big house off Commonwealth Avenue, directly over those Henley occupied, but two flights higher up. This friend was a figure in the social set of the Back Bay. He talked to Hatch freely of Cabell.
"He's a good fellow," he explained, "one of the best I ever met, and comes of one of the best families Virginia ever had-a true F. F. V. He's pretty quick tempered and all that, but an excellent chap, and everywhere he has gone here he has made friends."
"He used to be in love with Miss Lipscomb of Virginia, didn't he?" asked Hatch, casually.
"Used to be?" the other repeated with a laugh. "He is in love with her. But recently he understood that she was engaged to Weldon Henley, a broker-you may have heard of him?-and that, I suppose, has dampened his ardor considerably. As a matter of fact, Cabell took the thing to heart. He used to know Miss Lipscomb in Virginia-she comes from another famous family there-and he seemed to think he had a prior claim on her."
Hatch heard all these things as any man might listen to gossip, but each additional fact was sinking into his mind, and each additional fact led his suspicions on deeper into the channel they had chosen.
"Cabell is pretty well to do," his informant went on, "not rich as we count riches in the North, but pretty well to do, and I believe he came to Boston because Miss Lipscomb spent so much of her time here. She is a beautiful young woman of twenty-two and extremely popular in the social world everywhere, particularly in Boston. Then there was the additional fact that Henley was here."
"No chance at all for Cabell?" Hatch suggested.
"Not the slightest," was the reply. "Yet despite the heartbreak he had, he was the first to congratulate Henley on winning her love. And he meant it, too."
"What's his attitude toward Henley now?" asked Hatch. His voice was calm, but there was an underlying tense note imperceptible to the other.
"They meet and speak and move in the same set. There's no love lost on either side, I don't suppose, but there is no trace of any ill feeling."
"Cabell doesn't happen to be a vindictive sort of man?"
"Vindictive?" and the other laughed. "No. He's like a big boy, forgiving, and all that; hot-tempered, though. I could imagine him in a fit of anger making a personal matter of it with Henley, but I don't think he ever did."
The mind of the newspaper man was rapidly focusing on one point; the rush of thoughts, questions and doubts silenced him for a moment. Then:
"How long has Cabell been in Boston?"
"Seven or eight months-that is, he has had apartments here for that long-but he has made several visits South. I suppose it's South. He has a trick of dropping out of sight occasionally. I understand that he intends to go South for good very soon. If I'm not mistaken, he is trying now to rent his suite."
Hatch looked suddenly at his informant; an idea of seeing Cabell and having a legitimate excuse for talking to him had occurred to him.
"I'm looking for a suite," he volunteered at last. "I wonder if you would give me a card of introduction to him? We might get together on it."
Thus it happened that half an hour later, about ten minutes past nine o'clock, Hatch was on his way to the big apartment house. In the office he saw the manager.