Dan left the Mayfair house very mournfully, feeling that Sir John was indeed master of the situation. By a skilful appeal to the generous emotions of youth, to the boy’s honour and to the girl’s affections, he had procured a respite of twelve months, during which time the lovers could do nothing, bound as they were by silken threads. This would give Curberry time to push his suit, and there was always a chance that Dan would come to grief in one of his aerial trips in which case Lillian would certainly be driven to marry her titled swain. Halliday knew nothing of Moon’s reckoning on these points, or he would have only accepted the situation on condition that Curberry was not to meet or write to the girl oftener than himself. Logically speaking, the peer and the commoner should have been placed on the same footing. But Dan’s grief at the parting confused his understanding, and he had not been clever enough to seize his opportunity. Therefore Sir John, winning all along the line, had cleared the path for Curberry, and had more or less blocked it for Dan. But, as yet, the young man did not grasp the full extent of Sir John’s worldly wisdom.

What Halliday had to do — and this dominated his mind immediately he left the house — was to solve the mystery of Sir Charles’s death. The sooner he captured the false Mrs. Brown, who, presumably, had murdered the old man, the sooner would he lead Lillian to the altar. Therefore he was feverishly anxious to begin, but for the life of him he did not see how to make a start. He had absolutely no experience of what constituted the business of a detective, and was daunted at the outset by the difficulties of the path. All the same he never thought of halting, but pressed forward without a pause. And the first step he took was to consult a friend, on the obvious assumption that two heads are better than one.

It was Freddy Laurance whom he decided to interview, since that very up-to-date young journalist knew everyone of any note, and almost everything of interest, being, indeed, aware of much of which the ordinary man in the street was ignorant. He and Dan had been to Oxford together, and for many years had been the best of friends. Laurance had been brought up in the expectation of being a rich man. But over-speculation ruined his father, and on leaving the university he was thrown unprepared on the world to make his money as best he could, without any sort of training in particular. Hearty praise from an expert for three or four newspaper articles suggested journalism, and having an observant eye and a ready pen, the young man was successful from the beginning. For a time he was a free-lance, writing indiscriminately for this journal and for that, until the proprietor of “The Moment”, a halfpenny daily, secured his exclusive services at a salary which procured Freddy the luxuries of life. This was something to have achieved at the age of five and twenty.

“The Moment” was a bright shoot-folly-as-it-flies sort of journal, which detailed the news of the day in epigrammatic scraps. Its longest articles did not exceed a quarter of a column, and important events were usually restricted to paragraphs. It, indeed, skimmed the cream of events, and ten minutes’ study of its sheets gave a busy man all the information he required concerning the doings of humanity. Also it daily published an extra sheet concerned entirely with letters from the public to the public, and many of these were prolix, as the paragraph rule did not apply to this portion of the journal. People wrote herein on this, that, and the other thing, ventilating their ideas and suggesting schemes. And as many wrote many bought, so that friends and relatives might read their letters, therefore vanity gave “The Moment” quite a large circulation independent of its orthodox issue. The proprietor made money in two ways; by supplying gossip for curious people, and by giving vain persons the chance of seeing themselves in print. Seeing what human nature is, it is scarcely to be wondered at that “The Moment” was a great success, and sold largely in town and country.

Freddy’s post was that of a roving correspondent. Whenever any event of interest took place in any of the four corners of the globe, Laurance went to take notes on the spot, and his information was boiled down into concise illuminative paragraphs. Indeed, the older journalists said that it was hardly worth while for him to make such long journeys for the sake of condensed-milk news; but, as Freddy’s details were always amusing as well as abrupt, the editor and the public and the proprietor were satisfied. A man who can flash a vivid picture into the dullest mind in few words is well worth money. Therefore was Laurance greatly appreciated.

Dan walked to a grimy lane leading from Fleet Street with some doubt in his puzzled mind as to whether Freddy would be in his office. At a moment’s notice the man would dart off to the ends of the earth, and was more or less on the move through the three hundred and sixty-five days of the year. But, of late, sensational events had concentrated themselves in England, so Dan hoped that his friend would be on the spot. An inquiry from the gorgeous individual who guarded the entrance to the red brick building wherein “The Moment” was printed and published and composed, revealed that Mr. Laurance was not only in London, but in his office at the very second, so Dan sent up his name, and rejoiced at the catching of this carrier-pigeon. And it was a good omen also that Freddy saw him straight away, since he generally refused himself to every one on the plea of business.

“But I couldn’t resist seeing you, Dan,” remarked Mr. Laurance, when he had shaken hands, before supplying his visitor with a cigarette and a chair. “I was coming to see you, if the mountain hadn’t come to Mahomet!”

Dan lighted up, and through the smoke of tobacco stared inquisitively at his friend, wondering what this introductory remark meant. Laurance 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, Mahomet,” 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 enquired.

“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 you 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 efforts 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 it 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 thought 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 light, and so did everyone 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 questioned 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 so easily as the 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 these 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, suggestive of drowsiness. Indeed, I used that word, and Tenson thought of some kind of chloroform used, perhaps, to stupefy the victim before killing him. But there was no odour about the mouth or nose.”

“On the handkerchief, perhaps?” suggested the reporter.

“No. Tenson smelt the handkerchief.”

“Well, if this Mrs. Brown used this perfume, you and Miss Moon and Mrs. Bolstreath must have smelt it on her in the hall. I understand from Durwin that you all three saw the woman.”

“Yes. And Lillian, poor girl, persuaded her father to see the wretch. But we did not smell the perfume on the woman. Tenson or Durwin — I forget which — asked us that question.”

“Humph!” said Laurance, after a pause; “it may be a kind of trade-mark, like the fly business.” He took a note. “I shall use this evidence in my letter to the public. I suppose, Dan, you would recognise the scent again?”

“Oh, yes! I have a keen sense of smell, you know. But I don’t expect I shall ever drop across this particular fragrance, Freddy.”

“There’s always Monsieur Chance, you know,” remarked Laurance, tapping his white teeth with a pencil. “Perhaps the gang use this scent so as to identify one another — in the dark it may be-like cats. How does that strike you?”

“As purely theoretical,” said Dan, with a shrug, and reached for another cigarette; “it’s a case of perhaps, and perhaps not.”

Laurance assented. “But everything so far is theoretical in this case,” he argued; “you have told me all you know?”

“Every bit, even to my year of probation. Do you know Curberry?”

“Yes. He was a slap-up barrister. A pity he got title and money, as he has left the Bar, and is a good man spoiled. Lucky chap all the same, as his uncle and cousin both died unexpectedly, to give him his chance of the House of Lords.”

“How did they die?”

“Motor accident. Car went over a cliff. Only the chauffeur was saved, and he broke both legs. Do you know the present Lord Curberry?”

“I have seen him, and think he’s a dried-up, cruel-looking beast,” said Dan, with considerable frankness. “I’d rather see Lillian dead than his wife.”

“Hear, hear!” applauded Laurance, smiling. “The girl’s too delightful to be wasted on Curberry. You have my blessing on the match, Dan.”

“Thanks,” said Dan ruefully, “but I have to bring it off first. Sir John’s infernally clever, and managed to get both Lillian and I to consent to let matters stand over for a year, during which time I guess he’ll push Curberry’s suit. But I can trust Lillian to be true to me, bless her! and Mrs. Bolstreath is quite on our side. After all,” murmured the young man disconsolately, “it’s only fair that Sir Charles should be avenged. Perhaps it would be selfish for Lillian and I to marry and live happy ever afterwards, without making some attempt to square things. The question is how to start. I’m hanged if I know, and so I came to you.”

“Well,” said Laurance thoughtfully, “there’s a hope of Monsieur Chance, you know. In many ways you may stumble on clues even without looking for them, since this gang — if it exists — must carry on an extensive business. All you can do, Dan, is to keep your eyes and ears and nose open — the last for that scent, you know. On my part I shall write the letter, and publish it in the annex of ‘The Moment’. Then we shall see what will happen.”

“Yes, I think that’s about the best way to begin. Stir up the muddy water, and we may find what is at the bottom of the pond. But there’s one thing to be considered, and that is money. If I’m going to hunt for these scoundrels I need cash, and to own up, Freddy, I haven’t very much.”

“You’re so beastly extravagant,” said Laurance grinning, “and your private income goes nowhere.”

“Huh! what’s five hundred a year?”

“Ten pounds a week, more or less. However, there’s your aviation. I hear that you take people on flights for money?”

Dan nodded. “It’s the latest fashionable folly, which is a good thing for me, old son. I get pretty well paid, and it means fun.”

“With some risk of death,” said Laurance drily.

“Well, yes. But that is a peculiarity of present-day fun. People love to play with death — it thrills them. However, if I am to hunt for the assassin of Sir Charles, I can’t give much attention to aviation, and I repeat that I want money. Oceans of it.”

“Would two thousand pounds suit you?”

“Rather. Only I’m not going to borrow from you, old man, thank you.”

“I haven’t that amount to lend,” said Freddy, drily; “but you must have seen, if you read our very interesting paper, that our proprietor has offered a prize of two thousand pounds for a successful flight from London to York.”

“A kind of up-to-date Dick Turpin, I suppose,” laughed Dan, rising and stretching his long limbs. “Good, I’ll have a shot; I may win.”

“You will, if you use a Vincent machine.”

“Vincent, Vincent? Where have I heard that name?”

“Everywhere, if you knew anything of the aviation world,” snapped Laurance rather crossly, for at times Dan’s indolence in acquiring necessary information annoyed him. “Solomon Vincent, who has been inventing airships and new-fangled aeroplanes for ever so long.”

“Yes, yes! I remember now. He’s a genius. Everyone knows him.”

“Everyone knows of him, except yourself; but no one knows him personally. He lives a secluded life up in Hillshire, on the borders of the moors, where he can find wide space for his experiments in aerial craft. I interviewed him a year ago, and — and —” Laurance blushed red.

“Hullo, what’s this?” asked Dan shrewdly. “Can it be that the inventor has a daughter fair?”

“A niece,” retorted Laurance, recovering; “why shouldn’t I be in love as well as you, Halliday? However, that doesn’t matter.”

“It matters a great deal to you.”

“Never mind. What you have to do is to secure one of Vincent’s machines and try for this race. If you win the prize you will have heaps of money to search for the gang. But why doesn’t Miss Moon —”

“I don’t take Lillian’s money,” said Dan curtly, and blushed in his turn. “It is a good idea, Freddy. How can I get hold of the machine?”

“I shall take you up to Hillshire next week, and you can see Vincent for yourself. He can talk to you, and —”

“And you can talk to the niece. What’s her name?”

“Oh, shut up and get out!” said Laurance, turning away, “you’re interrupting my work.”

“Going to write a letter to the beloved,” said Dan, leisurely making for the door. “All right, old son, I’ll go! You know my address, so write me when you want me. I’d like to see Vincent’s machines, as I hear he has made several good improvements, and everything tells in a race. Salaam!”

“Keep your eyes open,” Laurance called after him; “remember Monsieur Chance may prove to be our best friend.”

Dan departed, shrugging his shoulders. “I don’t believe in heaven-sent miracles,” were his last words. But they were wasted on Freddy, for that alert young man was already buried in his work. It was painful to witness such industry, in Halliday’s opinion.

In an inquiring frame of mind, the amateur detective strolled along Fleet Street, thinking of Lillian instead of keeping his wits about him, as Freddy had requested. It seemed impossible that he should strike on a clue without deliberately searching for it, which he did not feel inclined to do at the moment. Monsieur Chance, indeed! He was a mythical personage in whom this sceptical young man did not believe. Besides, love dominated his thoughts to the exclusion of minor matters, and he dreamed about his darling all along the Strand. Thus he did not look where he was going, and stumbled into the midst of a Charing Cross crowd, where a motor had broken down after colliding with a ‘bus. A policeman was conversing with the chauffeur and the ‘bus driver, who were conversing abusively with one another. The crowd blocked the street and stopped the traffic in order to enjoy the conversation, which left nothing to be desired in the way of free language. Dan halted idly as a spectator, not because he wished to be one, but for the very simple reason that he could not get through the crowd into Trafalgar Square.

Thrust up against one man, and wedged in by two others, and surrounded by hundreds, he grumbled at the delay, and peered over shoulders to see when the incident would end. As he did so, he suddenly in his mind’s eye saw a vision of Sir Charles lying dead in the well-lighted library. While wondering why he thought of the crime at this particular moment, he became aware that a familiar scent assailed his nostrils, the scent about which he had talked to Durwin and Tenson and Laurance. Nosing like a hound, he tried to find the person from whom it emanated, and almost immediately fixed on a spectator at his elbow. A moment later the man turned, and Dan found himself face to face with Marcus Penn.