Coquenil's effort during the next month might be set forth in great detail. It may also be told briefly, which is better, since the result rather than the means is of moment.

The detective began by admitting the practical worthlessness of the evidence in hand against this formidable adversary, and he abandoned, for the moment, his purpose of proving that De Heidelmann-Bruck had killed Martinez. Under the circumstances there was no way of proving it, for how can the wheels of justice be made to turn against an individual who absolutely controls the manner of their turning, who is able to remove annoying magistrates with a snap of his fingers, and can use the full power of government, the whole authority of the Prime Minister of France and the Minister of Justice for his personal convenience and protection?

The case was so extraordinary and unprecedented that it could obviously be met only (if at all) by extraordinary and unprecedented measures. Such measures Coquenil proceeded to conceive and carry out, realizing fully that, in so doing, he was taking his life in his hands. His first intuition had come true, he was facing a great criminal and must either destroy or be destroyed; it was to be a ruthless fight to a finish between Paul Coquenil and the Baron de Heidelmann-Bruck.

And, true to his intuitions, as he had been from the start, M. Paul resolved to seek the special and deadly arm that he needed against this sinister enemy in the baron's immediate entourage; in fact, in his own house and home. That was the detective's task, to be received, unsuspected, as an inmate of De Heidelmann-Bruck's great establishment on the Rue de Varennes, the very center of the ancient nobility of Paris.

In this purpose he finally succeeded, after what wiles and pains need not be stated, being hired at moderate wages as a stable helper, with a small room over the carriage house, and miscellaneous duties that included much drudgery in cleaning the baron's numerous automobiles. It may truthfully be said that no more willing pair of arms ever rubbed and scrubbed their aristocratic brasses.

The next thing was to gain the confidence, then the complicity of one of the men servants in the hÔtel itself, so that he might be given access to the baron's private apartments at the opportune moment. In the horde of hirelings about a great man there is always one whose ear is open to temptation, and the baron's household was no exception to this rule. Coquenil (known now as Jacques and looking the stable man to perfection) found a dignified flunky in black side whiskers and white-silk stockings who was not above accepting some hundred-franc notes in return for sure information as to the master's absences from home and for necessary assistance in the way of keys and other things.

Thus it came to pass that on a certain night in August, about two in the morning, Paul Coquenil found himself alone in the baron's spacious, silent library before a massive safe. The opening of this safe is another matter that need not be gone into—a desperate case justifies desperate risk, and an experienced burglar chaser naturally becomes a bit of a burglar himself; at any rate, the safe swung open in due course, without accident or interference, and the detective stood before it.

All this Coquenil had done on a chance, without positive knowledge, save for the assurance of the black-whiskered valet that the baron wrote frequently in a diary which he kept locked in the safe. Whether this was true, and, if so, whether the baron had been mad enough to put down with his own hand a record of his own wickedness, were matters of pure conjecture. Coquenil was convinced that this journal would contain what he wanted; he did not believe that a man like De Heidelmann-Bruck would keep a diary simply to fill in with insipidities. If he kept it at all, it would be because it pleased him to analyze, fearlessly, his own extraordinary doings, good or bad. The very fact that the baron was different from ordinary men, a law unto himself, made it likely that he would disregard what ordinary men would call prudence in a matter like this; there is no such word as imprudence for one who is practically all-powerful, and, if it tickled the baron's fancy to keep a journal of crime, it was tolerably certain he would keep it.

The event proved that he did keep it. On one of the shelves of the safe, among valuable papers and securities, the detective found a thick book bound in black leather and fastened with heavy gold clasps. It was the diary.

With a thrill of triumph, Coquenil seized upon the volume, then, closing the safe carefully, without touching anything else, he returned to his room in the stable. His purpose was accomplished, and now he had only one thought—to leave the hÔtel as quickly as possible; it would be a matter of a few moments to pack his modest belongings, then he could rouse the doorkeeper and be off with his bag and the precious record.

As he started to act on this decision, however, and steal softly down to the courtyard, the detective paused and looked at his watch. It was not yet three o'clock, and M. Paul, in the real burglar spirit, reflected that his departure with a bag, at this unseasonable hour, might arouse the doorkeeper's suspicion; whereas, if he waited until half past five, the gate would be open and he could go out unnoticed. So he decided to wait. After all, there was no danger, the baron was away from Paris, and no one would enter the library before seven or eight.

While he waited, Coquenil opened the diary and began to read. There were some four hundred neatly written pages, brief separate entries without dates, separate thoughts as it were, and, as he turned through them he found himself more and more absorbed until, presently, he forgot time, place, danger, everything; an hour passed, two hours, and still the detective read on while his candle guttered down to the stick and the brightening day filled his mean stable room; he was absolutely lost in a most extraordinary human document, in one of those terrible utterances, shameless and fearless, that are flung out, once in a century or so, from the hot somber depths of a man's being.

Coquenil had reached this point in his reading and was pressing on through the pages, utterly oblivious to everything, when a harsh voice broke in upon him: "You seem to have an interesting book, my friend?"

Looking up with a start, M. Paul saw De Heidelmann-Bruck himself standing in the open doorway. His hands were thrust carelessly in his coat pockets and a mocking smile played about his lips, the smile that Coquenil had learned to fear.

"It's more than interesting, it's marvelous, it's unbelievable," answered the detective quietly. "Please shut that door. There's a draught coming in."

As he spoke he sneezed twice and reached naturally toward his coat as if for a handkerchief.

"No, no! None of that!" warned the other sharply. "Hands up!" And Coquenil obeyed. "My pistol is on you in this side pocket. If you move, I'll shoot through the cloth."

"That's a cowboy trick; you must have traveled in the Far West," said M. Paul lightly.

"Stand over there!" came the order. "Face against the wall! Hands high! Now keep still!"

Coquenil did as he was bidden. He stood against the wall while quick fingers went through his clothes, he felt his pistol taken from him, then something soft and wet pressed under his nostrils. He gasped and a sweetish, sickening breath filled his lungs, he tried to struggle, but iron arms held him helpless. He felt himself drifting into unconsciousness and strove vainly against it. He knew he had lost the battle, there was nothing to hope for from this man—nothing. Well—it had been a finish fight and—one or the other had to go. He was the one, he was going—going. He—he couldn't fix his thoughts. What queer lights! Hey, CÆsar! How silly! CÆsar was dead—Oh! he must tell Papa Tignol that—a man shouldn't swear so with a—red—nose. Stop! this must be the—end and——

With a last rally of his darkening consciousness, Coquenil called up his mother's face and, looking at it through the eyes of his soul, he spoke to her across the miles, in a wild, voiceless cry: "I did the best I could, little mother, the—the best I—could."

Then utter blackness!