In his anxiety to learn the truth Dan was perfectly willing to be arrested on whatever charge Penn might wish to bring against him. After all, publicity was what he chiefly aimed at, and if he gave his reasons for threatening the secretary, he felt confident that the man would find it difficult to clear his character. Certainly Halliday had not intended to take Penn's life, and had not the man been such a coward he would have simply laughed at the idea of being tilted out of the machine. But his nerves, shaken by the possible danger, had given way, and he had said much which he would have preferred to keep locked up in his heart. But that the aeroplane, by dipping so low, had afforded Penn the chance of escape at the risk of a rough fall, he would have spoken at greater length. And yet, after turning the matter over in his own mind, Dan could not be sure of this. But this much Halliday had learned. A gang assuredly existed, and the perfume was a sign of recognition amongst the members, who apparently followed each other's trails by scent. Penn declined to say if his late employer had been done to death by the fraternity, but the perfume on the dead man's clothes answered this question very positively. Also the secretary had denied that the false Mrs. Brown belonged to the gang, a statement which was absurd, as undoubtedly she was the emissary employed to bring about the death. Finally, the fact that Mrs. Jarsell used the Sumatra scent brought her into connection with the Hampstead crime; whatever Penn might say Dan felt that he had struck a trail, which would end in the capture of Moon's assassin and the breaking up of a dangerous organization. On reflection he concluded that Penn would have said very little more, even though face to face with what he believed to be imminent death. He had hinted sufficiently to show that revelation was dangerous not only to himself but to Halliday, for if the gang learned that their secret was betrayed, it was certain that death would be portioned out to the man who heard, as well as to the man who spoke. On this assumption Dan felt confident that Penn would take no action in the matter, and would probably hold his tongue about the adventure. If he told any of the gang to which he presumably belonged, he would have to admit that he had betrayed the secret of the perfume, in which case he would assuredly be killed by his unscrupulous associates. The death of Dan, as the young man believed, would follow, but he also believed that by taking care of his own skin Penn would remove any risk of vengeance following himself; therefore he was not surprised when he heard nothing from Penn, or of Penn during the days that passed before the morning of the great race. Meanwhile he detailed the conversation to Laurance. That young gentleman had returned to town with some regret since Mildred Vincent was not by his side. But to assure himself of an early marriage by securing a steady income, he flung himself into journalistic work with redoubled energy, working night and day to gain an increased salary. He was in his office employed on a political article when Dan presented himself, and was not overpleased to give up even a moment of his precious time. In fact, he grumbled. "I wish you would come after business hours, Halliday," he said testily. "Oh, fudge," retorted Dan lightly. "A journalist hasn't any business hours. Like a king, he is always in harness. Why do you require me to tell you such elementary truths, Freddy?"

"I have an important article to write."

"Well, then, you can write it in ten minutes or so. I shan't keep you long." Laurance pushed away his writing paper, leaned back in his chair, and reached for a cigarette. "What is it, then?" he asked resignedly. Dan paced the office and related his adventure. "So you see, old son, that the perfume is of great importance, as I always suspected." Laurance nodded gravely. "It appears so. But if what you think is true, would the man have disclosed a secret dangerous to his own safety?"

"People will disclose anything when on the rack," replied Dan with a shrug, "and the aeroplane was my rack. The fool really believed that I would tilt him overboard, and therefore said what he did say to save his confounded skin. If he had not escaped so cleverly he would have admitted more." "I doubt it. From the hint he gave, if it was death for him not to confess to you, because you could kill him, it was equally death for him to speak, if his associates are prepared to murder him for babbling. However, we are now certain that the gang alluded to by Sir Charles does exist. Undoubtedly he was got out of the way since he knew too much."

"It is a pity he did not reveal his knowledge to Durwin."

"He intended to do so, but was murdered before Durwin arrived, as we know. By the way, Durwin is as keen as we are over this search. I met him the other day and he said that he was hunting everywhere for evidence. Why not tell him what you have learned, Dan? He can make Penn speak out."

"Penn won't speak further," denied Dan abruptly. "I think, as it is, he dreads the vengeance of his comrades."

"Durwin belongs to Scotland Yard, and has powers to drive Penn into a corner, so he may be able to force confession. I think you should consult with Durwin about the matter."

"After the race then."

"Why not before the race, which does not take place for a couple of days?"