When Richard Duvall left Dufrenne, the curio dealer, in Piccadilly Circus, and started after the man who had purchased the box of powder in the barber shop, he realized to the full the hopelessness of his task. The man had left the shop at least two minutes before Dufrenne came out—perhaps more, and another minute had been consumed by the latter in telling his story. Three minutes' start, in a crowded street at night, was a handicap which the detective could scarcely hope to overcome.

He hurried along in the general direction the fellow had taken, trying to form in his mind a clear picture of his appearance. In the dim light before the shop he had not been able to observe him closely, nor had there, indeed, appeared any very good reason for doing so; he had thought the man but a belated customer of the place and had barely glanced at him.

His experience in summing up at a glance the general characteristics of those he met, however, stood him in good stead—he remembered that the man had worn a long brown overcoat, a derby hat, and carried in his hand a small satchel. The latter, which Dufrenne had failed to mention, indicated a traveler—the man's words to Seltz, on purchasing the box of powder, seemed to confirm it. The man had walked, apparently, instead of taking a cab. Charing Cross station was but a short distance away. What more natural, Duvall reasoned, than that the man he was following, was on his way to take a train?

Following this line of reasoning, the detective walked hastily in the direction of Charing Cross, dodging in and out among the passers-by, and eying keenly everyone he met, in the hope that he might discover the man with the satchel. He was, however, doomed to disappointment. After spending over fifteen minutes in Charing Cross station, watching the crowds at the booking offices, the telegraph and telephone booths and the restaurant, he concluded that he had been mistaken in his course of reasoning and reluctantly turned his steps once more toward the shop of M. Perrier. There was, of course, still the chance that his deductions had been wrong. Seltz might still have the snuff box in his possession, and the man with the satchel be merely a harmless individual who used rice powder after shaving. He almost reproached himself for having wasted so much time, and hurried along through Piccadilly Circus, in a state of considerable perplexity.

As he came up to the shop, he saw Dufrenne standing before the window, his eyes glued to the pane. Something in his astonished expression attracted the detective's attention at once. He tapped the curio dealer lightly on the shoulder.

Dufrenne turned suddenly, much startled, then recognizing Duvall, drew him to one side. "I have watched the door every minute since you left," he said in a trembling voice. "Seltz did not come out—yet he is not inside. No one is there but Monsieur Perrier."

Duvall started back with a muttered exclamation. "You—you must be mistaken," he cried.

"Look!" The Frenchman pointed to the window. Duvall glanced within. The proprietor of the place was its only occupant.

The detective turned to his companion and nodded. "Come inside," he said, shortly, and striding up to the door, threw it open and entered the place.

Monsieur Perrier, startled half out of his wits by the suddenness with which Duvall entered the room, dropped the comb with which he had been arranging his hair and turned with an alarmed face. "The shop—it is closed for the night," he said. "My men have all gone home."

"Has Seltz gone?" asked Duvall, sharply.

"Seltz? Surely. He left immediately after shaving this gentleman." Perrier indicated Dufrenne with a fat and trembling forefinger. "Is anything wrong, gentlemen? Was the shave not satisfactory?"

Duvall looked at the curio dealer with a smile of chagrin. "It's perfectly clear, Dufrenne," he said, somewhat crestfallen. "Our man went out as we were walking up the street—while you were telling me what happened in the shop."

The little old man nodded. Monsieur Perrier continued to gaze at his visitors. "What is it you wish, gentlemen?" he presently inquired.

"Where does Seltz live?" Duvall demanded, sharply.

"Alas—I do not know. He has worked for me but three months. I knew nothing of him—nothing at all. He—he asked for leave of absence yesterday—he was to be gone a week, but to-night he told me that he would not go."

Duvall's eyes lit up. He turned to Dufrenne. "After what happened—to-night," he said, significantly, "he feared to leave—thinking that his going away would be an admission of his guilt."

Again Dufrenne nodded. Monsieur Perrier looked at them with bulging eyes. "Guilt!" he exclaimed. "Has this fellow Seltz been doing anything he should not?"

"Possibly," Duvall ejaculated, dryly. "Do you happen to know where he was going?"

"He—he said something about visiting his parents. Oh—gentlemen—I beg of you, do not cause any scandal—it would ruin my trade. I shall discharge the fellow at once."

"You will do nothing of the sort," exclaimed Duvall, angrily. "If he reports for duty to-morrow, say nothing to him of our visit, or it will be worse for you." He leaned toward the terrified barber. "I am a detective," he said, shortly. "Be careful what you do."

Monsieur Perrier sank upon his knees, his hands lifted in supplication. "Mon Dieu—what shall I do—my business—it will be desolated—what shall I do?"

"Get up, and hold your tongue first of all. After that, tell me, if you can, where it was that Seltz intended to go, to visit his parents?"

"He spoke of Brussels—he intended to take the night boat from Harwich to Antwerp. I heard him discussing his plans with one of the other men."

"Brussels!" Duvall hurriedly glanced at his watch. "There's just time, if we hurry—come." He turned to Dufrenne, excitement showing in every line of his face. As he hurried toward the door he spoke over his shoulder to Monsieur Perrier. "Don't open your mouth to a soul—do you hear? If you do, you'll get yourself into a peck of trouble." The last thing they heard as they left the shop was the barber's howls of assent.

At the corner Duvall signaled a passing cab. "Liverpool Street station, in a hurry," he cried. "Half a crown extra, if you make the boat train for Harwich."

Dufrenne gazed at his companion in bewilderment. "I do not understand, Monsieur Duvall," he began, but the detective cut him short. "The thing is as plain as a pipe stem," he said. "Seltz expected to get the snuff box from the Ambassador's man this afternoon, and had made his arrangements to leave with it for Brussels at once. The events of the evening—culminating in NoËl's murder, made him fear to do so. He realized that the note, delivered to him by one of the Ambassador's servants, might attract suspicion toward him, and therefore wisely made up his mind to remain quietly where he was, sending the box by some friend. He dared not hand the box to him at any place outside the shop, for fear he might be watched. No doubt he arranged with his friend to come to the place just before closing, and to pretend to buy the face powder, as you saw him do. Seltz had only to turn the powder out of the package, put the snuff box inside, and the thing was done. This he no doubt did at some opportune moment during the evening, when he was certain he was not observed. It is a mighty clever scheme—I'll admit. You saw nothing suspicious about the transaction, and I confess that I did not realize its significance at the time. Naturally the man to whom he gave the box will make for Brussels at once, since it was to that point that Seltz intended going. No doubt he was operating in the interests of someone else—some third person to whom the box is of great value, and who has agreed to pay a large sum for it on delivery. You saw the fellow who bought the powder hand Seltz money—how much you could not tell. It may be that Seltz was obliged to divide the reward with his friend, and that the latter has already turned over to Seltz his share in advance. Of that we cannot be certain, nor is it material. Seltz is undoubtedly guilty of the murder of the man NoËl, but to stay here and arrest him now would only defeat the object we have in view. After the box has been recovered, we can return and deal with Seltz. You may be quite sure he will not dare to run away, for fear that by so doing he would admit his guilt."

Dufrenne looked at the detective in admiration. "You reason well, monsieur," he remarked. "But why should they be taking the box to Brussels?"

"That I cannot tell you, of course, except that, as I said before, the plot to steal it inevitably originated there. We shall learn more to-morrow, after we have arrived in the city. The next thing to be done is to find our man."

They arrived at Liverpool Street station just in time to swing aboard the train for Harwich as it was pulling out. There were not many passengers—they found themselves in a smoking-compartment quite to themselves.

"There is no use in attempting to do anything until we reach Harwich," the detective remarked, pulling his hat over his eyes. He leaned back and began to speculate disgustedly upon the events of the day. Married at noon—torn from his wife within an hour—in London at night—a murder—and now a wild chase to Brussels after a snuff box. It seemed almost ludicrous. He smiled grimly. He had not expected to spend in quite this way the first twelve hours of his honeymoon.