was rather like Dan in personal appearance, being tall and slim and clean-shaven, with Greek features and an aristocratic look. But he was decidedly fair, as Halliday was decidedly dark, and his eyes were less like those of an eagle than the eyes of the aviator. But then Laurance was not accustomed to the boundless spaces of the air, although he had twice ascended in an airship; therefore the new expression of the new race was wanting. Nevertheless, he looked a capable, alert young man, able to get the full value out of every minute. He was an admirable type of the restless, present-day seeker. "Well, Mahommed," said Dan, leisurely, "here's the mountain. What have you to say to it?"
"That murder of Sir Charles Moon." Halliday quivered with surprise. It was so amazing that Laurance should hit upon the very subject, which employed his own thoughts. "Yes?" he inquired. "You are engaged to Miss Moon; you were in the house when the crime was committed; you saw the body; you-"
"Stop! Stop! I was not in the house when the crime was committed. I returned there from the theatre some time later-in fact about midnight. I certainly did see the body. As to being engaged to Miss Moon-h'm! I came to see about that, Freddy."
"The deuce you did. Great minds jump. What?" Laurance puffed a blue cloud, sat down astride a chair and leaned his arms on the back. "Strange!"
"That you and I should be on the hunt. Well it is."
"On the hunt!" echoed Laurance, staring. "What do you mean?"
"I should rather ask that question of you," said Dan drily. "Sir Charles is dead and buried these many weeks, and the woman who assassinated him can't be found, in spite of the reward and the effort of the police. Why, at this late hour, do you wish to rake up stale news? I thought that The Moment was more up-to-date."
"It will be very much up-to-date when the next murder is committed," observed Laurance, grimly and significantly. The legs of Dan's chair grated, as he pushed back in sheer surprise. "What do you mean by the next murder?" he demanded sharply. "Well, this gang-"
"Gang! gang! Who says there is a gang?" and Dan's thoughts flew back to Durwin's reason for visiting Sir Charles. "Humph!" growled Laurance, thrusting his hands into his pockets. "I'm disappointed. I thought you knew more."
"I know a good deal," retorted the other quickly, "but I don't intend to talk to you about what I know until I learn your game."
"What about your own?" "That comes later also," said Halliday promptly. "Go on! I want to know why you rake up Moon's murder."
"Naturally you do, seeing you are engaged to the daughter."
"Am I? I am not quite sure. She loves me and I love her, but the new baronet wants her to marry Lord Curberry. She refused, and I kicked up a row some hours back. Result, we are on probation for one year, during which time I am to discover the assassin of Sir Charles."
"And if you don't?"
"Time enough to talk about that when I fail," said Halliday coolly; "at least I have twelve months to hunt round. I came for your help, but it seems that you want mine. Why?" Freddy, through sheer absence of mind, flung away a half-smoked cigarette and lighted another. Then he rose and strolled across the room to lean his shoulders against the mantelpiece. "We can help one another, I think," was his final observation. "I hope so. In any case I intend to marry Lillian. All the same, to pacify Sir John, I am willing to become a detective. You know my game. Yours?"
"Listen," said Laurance vivaciously. "I forgot all about the murder, since there seemed to be no chance of the truth coming to the light, and so did every one else for the same reason. But a few nights ago I was dining out, and met a chap called Durwin-"
"Scotland Yard man," interrupted Dan, nodding several times. "He came to see Sir Charles on business and found the corpse." "Just so. Well, after dinner we had a chat, and he told me that he was anxious to learn who killed Moon, because he didn't want any more murders of the kind to happen-as a police official, you understand."
"Strange he should be confidential on that point," murmured Halliday thoughtfully, "seeing that he wished his theory regarding a possible gang kept quiet, in the hope of making discoveries."
"He has changed his mind about secrecy, and so has Tenson," said Freddy. "Oh!" Dan raised his eyebrows. "The Inspector. You have seen him also?" Laurance nodded. "After I saw Durwin, and learned what he had to say I saw Tenson, and interviewed him. They told me about the fly on the neck, and remembering the case of the purple fern, and having regard to the fact that the fly in question was artificial, both men are inclined to believe in the existence of a gang, whose trade-mark the said fly is." Dan nodded again. "Quite so; and then Durwin came to see Moon and hear about the gang. He found him dead."
"So you said; so Durwin said," rejoined Laurance quietly. "It seems very certain, putting this and that together, that Sir Charles became dangerous to this gang, whatever it is, and wherever it exists, so was put to death by the false Mrs. Brown, who came expressly to kill him."
"So far I am with you on all fours," said Halliday. "Well?"
"Well, both Durwin and Tenson, dreading lest the gang may commit another crime, wish me to make the matter as public as I can, so as to frighten the beasts."
"H'm!" said Dan, looking at his neat brown boots. "They have changed their minds, it seems. Their first idea was to keep the matter quiet, so as to catch these devils red-handed. However, publicity may be a good thing. How do you intend to begin?"
"I have got facts from Tenson and from Durwin," said Freddy promptly; "and now, since you saw the body and found the fly, I want to get the facts from you. On what I acquire I shall write a letter in that extra sheet of ours, and you can be pretty certain from what you know of human nature that any amount of people will reply to my letter."
"They may reply to no purpose."
"I'm not so sure of that, Dan. If I mention the fly as a trade-mark and recall the strange case of the purple fern, some one may write about matters known to themselves from positive knowledge. If this gang exists, it has committed more murders than one, but the fly being a small insect may not have been noticed as a trade-mark in the other crimes. I wonder you spotted it anyhow."
"It was easily seen, being on the back of the neck near the wound. Besides, flies in November-the month of the murder-are rare. Finally Tenson discovered the fly to be artificial, which shows that it was purposely placed on the dead man's neck, near the wound. H'm!" he reflected, "perhaps someone may know of some crime with the fly trade-mark, and in that case we can be certain that such a gang does exist."
"So I think," cried Laurance quickly, "and for that reason I intend to start a discussion by writing an open letter. Publicity may frighten the beasts into dropping their trade; on the other hand, it may goad the gang into asserting itself. In either case the subject will be ventilated, and we may learn more or less of the truth."
"Yes. I think it's a good idea, Freddy. And the perfume? Did Durwin or the Inspector tell you anything about the perfume. No, I can see by your blank stare that they didn't. Listen, Freddy, and store this knowledge in your blessed brain, my son. It is a clue, I am sure," and Halliday forthwith related to his attentive listener details concerning the strange perfume which had impregnated the clothes of the dead man. "And Sir Charles hated perfumes," he ended, emphatically; "he didn't even like Lillian or Mrs. Bolstreath to use them, and they obeyed him." "Curious," mused the journalist, and idly scribbling on his blotting-paper; he was back at his desk by this time. "What sort of scent is it?"
"My dear chap, you ask me to describe the impossible," retorted Dan, with uplifted eyebrows. "How the deuce can I get the kind of smell into your head? It must be smelt to be understood. All I can say is that the perfume was rich and heavy,
