After leaving Notre-Dame, Paul Coquenil directed his steps toward the prefecture of police, but halfway across the square he glanced back at the church clock that shows its white face above the grinning gargoyles, and, pausing, he stood a moment in deep thought.

"A quarter to seven," he reflected; then, turning to the right, he walked quickly to a little wine shop with flowers in the windows, the Tavern of the Three Wise Men, an interesting fragment of old-time Paris that offers its cheery but battered hospitality under the very shadow of the great cathedral.

"Ah, I thought so!" he muttered, as he recognized Papa Tignol at one of the tables on the terrace. And approaching the old man, he said in a low tone: "I want you."

Tignol looked up quickly from his glass, and his face lighted. "Eh, M. Paul again!"

"I must see M. Pougeot," continued the detective. "It's important. Go to his office. If he isn't there, go to his house. Anyhow, find him and tell him to come to me at once. Hurry on; I'll pay for this."

"Shall I take an auto?"

"Take anything, only hurry."

"And you want me at nine o'clock?"

Coquenil shook his head. "Not until to-morrow."

"But the news you were going to tell me?"

"There'll be bigger news soon. Oh, run across to the church and tell Bonneton that he needn't come either."

"I knew it, I knew it," chuckled Papa Tignol, as he trotted off. "There's something doing!"

"'I want you,' he said in a low voice."

With this much arranged, Coquenil, after paying for his friend's absinthe, strolled over to a cab stand near the statue of Henri IV and selected a horse that could not possibly make more than four miles an hour. Behind this deliberate animal he seated himself, and giving the driver his address, he charged him gravely not to go too fast, and settled back against the cushions to comfortable meditations. "There is no better way to think out a tough problem," he used to insist, "than to take a very long drive in a very slow cab."

It may have been that this horse was not slow enough, for forty minutes later Coquenil's frown was still unrelaxed when they drew up at the Villa Montmorency, really a collection of villas, some dozens of them, in a private park near the Bois de Boulogne, each villa a garden within a garden, and the whole surrounded by a great stone wall that shuts out noises and intrusions. They entered by a massive iron gateway on the Rue Poussin and moved slowly up the ascending Avenue des Tilleuls, past lawns and trees and vine-covered walls, leaving behind the rush and glare of the city and entering a peaceful region of flowers and verdure where Coquenil lived.

The detective occupied a wing of the original Montmorency chateau, a habitation of ten spacious rooms, more than enough for himself and his mother and the faithful old servant, Melanie, who took care of them, especially during these summer months, when Madame Coquenil was away at a country place in the Vosges Mountains that her son had bought for her. Paul Coquenil had never married, and his friends declared that, besides his work, he loved only two things in the world—his mother and his dog.

It was a quarter to eight when M. Paul sat down in his spacious dining room to a meal that was waiting when he arrived and that Melanie served with solicitous care, remarking sadly that her master scarcely touched anything, his eyes roving here and there among painted mountain scenes that covered the four walls above the brown-and-gold wainscoting, or out into the garden through the long, open windows; he was searching, searching for something, she knew the signs, and with a sigh she took away her most tempting dishes untasted.

At eight o'clock the detective rose from the table and withdrew into his study, a large room opening off the dining room and furnished like no other study in the world. Around the walls were low bookcases with wide tops on which were spread, under glass, what Coquenil called his criminal museum. This included souvenirs of cases on which he had been engaged, wonderful sets of burglars' tools, weapons used by murderers—saws, picks, jointed jimmies of tempered steel, that could be taken apart and folded up in the space of a thick cigar and hidden about the person. Also a remarkable collection of handcuffs from many countries and periods in history. Also a collection of letters of criminals, some in cipher, with confessions of prisoners and last words of suicides. Also plaster casts of hands of famous criminals. And photographs of criminals, men and women, with faces often distorted to avoid recognition. And various grewsome objects, a card case of human skin, and the twisted scarf used by a strangler.

As for the shelves underneath, they contained an unequaled special library of subjects interesting to a detective, both science and fiction being freely drawn upon in French, English, and German, for, while Coquenil was a man of action in a big way, he was also a student and a reader of books, and he delighted in long, lonely evenings, when, as now, he sat in his comfortable study thinking, thinking.

Melanie entered presently with coffee and cigarettes, which she placed on a table near the green-shaded lamp, within easy reach of the great red-leather chair where M. Paul was seated. Then she stole out noiselessly. It was five minutes past eight, and for an hour Coquenil thought and smoked and drank coffee. Occasionally he frowned and moved impatiently, and several times he took off his glasses and stroked his brows over the eyes.

Finally he gave a long sigh of relief, and shutting his hands and throwing out his arms with a satisfied gesture, he rose and walked to the fireplace, over which hung a large portrait of his mother and several photographs, one of these taken in the exact attitude and costume of the painting of Whistler's mother in the Luxembourg gallery. M. Paul was proud of the striking resemblance between the two women. For some moments he stood before the fine, kindly face, and then he said aloud, as if speaking to her: "It looks like a hard fight, little mother, but I'm not afraid." And almost as he spoke, which seemed like a good omen, there came a clang at the iron gate in the garden and the sound of quick, crunching steps on the gravel walk. M. Pougeot had arrived.

M. Lucien Pougeot was one of the eighty police commissaries who, each in his own quarter, oversee the moral washing of Paris's dirty linen. A commissary of police is first of all a magistrate, but, unless he is a fool, he soon becomes a profound student of human nature, for he sees all sides of life in the great gay capital, especially the darker sides. He knows the sins of his fellow men and women, their follies and hypocrisies, he receives incredible confessions, he is constantly summoned to the scenes of revolting crime. Nothing, absolutely nothing, surprises him, and he has no illusions, yet he usually manages to keep a store of grim pity for erring humanity. M. Pougeot was one of the most distinguished and intelligent members of this interesting body. He was a devoted friend of Paul Coquenil.

The newcomer was a middle-aged man of strong build and florid face, with a brush of thick black hair. His quick-glancing eyes were at once cold and kind, but the kindness had something terrifying in it, like the politeness of an executioner. As the two men stood together they presented absolutely opposite types: Coquenil, taller, younger, deep-eyed, spare of build, with a certain serious reserve very different from the commissary's outspoken directness. M. Pougeot prided himself on reading men's thoughts, but he used to say that he could not even imagine what Coquenil was thinking or fathom the depths of a nature that blended the eagerness of a child with the austerity of a prophet.

"Well," remarked the commissary when they were settled in their chairs, "I suppose it's the Rio Janeiro thing? Some parting instructions, eh?" And he turned to light a cigar.

Coquenil shook his head.

"When do you sail?"

"I'm not sailing."

"Wha-at?"

For once in his life M. Pougeot was surprised. He knew all about this foreign offer, with its extraordinary money advantages; he had rejoiced in his friend's good fortune after two unhappy years, and now—now Coquenil informed him calmly that he was not sailing.

"I have just made a decision, the most important decision of my life," continued the detective, "and I want you to know about it. You are the only person in the world who will know—everything. So listen! This afternoon I went into Notre-Dame church and I saw a young girl there who sells candles. I didn't know her, but she looked up in a queer way, as if she wanted to speak to me, so I went to her and—well, she told me of a dream she had last night."

"A dream?" snorted the commissary.

"So she said. She may have been lying or she may have been put up to it; I know nothing about her, not even her name, but that's of no consequence; the point is that in this dream, as she called it, she brought together the two most important events in my life."

"Hm! What was the dream?"

"She says she saw me twice, once in a forest near a wooden bridge where a man with a beard was talking to a woman and a little girl. Then she saw me on a boat going to a place where there were black people."

"That was Brazil?"

"I suppose so. And there was a burning sun with a wicked face inside that kept looking down at me. She says she often dreams of this wicked face, she sees it first in a distant star that comes nearer and nearer, until it gets to be large and red and angry. As the face comes closer her fear grows, until she wakes with a start of terror; she says she would die of fright if the face ever reached her before she awoke. That's about all."

For some moments the commissary did not speak. "Did she try to interpret this dream?"

"No."

"Why did she tell you about it?"

"She acted on a sudden impulse, so she says. I'm inclined to believe her; but never mind that. Pougeot," he rose in agitation and stood leaning over his friend, "in that forest scene she brought up something that isn't known, something I've never even told you, my best friend."

"Tiens! What is that?"

"You think I resigned from the police force two years ago, don't you?"

"Of course."

"Everyone thinks so. Well, it isn't true. I didn't resign; I was discharged."

M. Pougeot stared in bewilderment, as if words failed him, and finally he repeated weakly: "Discharged! Paul Coquenil discharged!"

"Yes, sir, discharged from the Paris detective force for refusing to arrest a murderer—that's how the accusation read."

"But it wasn't true?"

"Judge for yourself. It was the case of a poacher who killed a guard. I don't suppose you remember it?"

M. Pougeot thought a moment—he prided himself on remembering everything. "Down near Saumur, wasn't it?"

"Exactly. And it was near Saumur I found him after searching all over France. We were clean off the track, and I made up my mind the only way to get him was through his wife and child. They lived in a little house in the woods not far from the place of the shooting. I went there as a peddler in hard luck, and I played my part so well that the woman consented to take me in as a boarder."

"Wonderful man!" exclaimed the commissary.

"For weeks it was a waiting game. I would go away on a peddling tour and then come back as boarder. Nothing developed, but I could not get rid of the feeling that my man was somewhere near in the woods."

"One of your intuitions. Well?"

"Well, at last the woman became convinced that they had nothing to fear from me, and she did things more openly. One day I saw her put some food in a basket and give it to the little girl. And the little girl went off with the basket into the forest. Then I knew I was right, and the next day I followed the little girl, and, sure enough, she led me to a rough cave where her father was hiding. I hung about there for an hour or two, and finally the man came out from the cave and I saw him talk to his wife and child near a bridge over a mountain torrent."

"The picture that girl saw in the dream!"

"Yes; I'll never forget it. I had my pistol ready and he was defenseless; and once I was just springing forward to take the fellow when he bent over and kissed his little girl. I don't know how you look at these things, Pougeot, but I couldn't break in there and take that man away from his wife and child. The woman had been kind to me and trusted me, and—well, it was a breach of duty and they punished me for it; but I couldn't do it, I couldn't do it, and I didn't do it."

"And you let the fellow go?"

"I let him go then, but I got him a week later in a fair fight, man to man. They gave him ten years."

"And discharged you from the force?"

"Yes. That is, in view of my past services, they allowed me to resign." Coquenil spoke bitterly.

"Outrageous! Unbelievable!" muttered Pougeot. "No doubt you were technically in the wrong, but it was a slight offense, and, after all, you got your man. A reprimand at the most, at the most, was called for, and not with you, not with Paul Coquenil."

The commissary spoke with deeper feeling than he had shown in years, and then, as if not satisfied with this, he clasped the detective's hand and added heartily: "I'm proud of you, old friend, I honor you."

Coquenil looked at Pougeot with an odd little smile. "You take it just as I thought you would, just as I took it myself—until to-day. It seems like a stupid blunder, doesn't it? Well, it wasn't a blunder; it was a necessary move in the game." His face lighted with intense eagerness as he waited for the effect of these words.

"The game? What game?" The commissary stared.

"A game involving a great crime."

"You are sure of that?"

"Perfectly sure."

"You have the facts of this crime?"

"No. It hasn't been committed yet."

"Not committed yet?" repeated the other, with a startled glance. "But you know the plan? You have evidence?"

"I have what is perfectly clear evidence to me, so clear that I wonder I never saw it before. Lucien, suppose you were a great criminal, I don't mean the ordinary clever scoundrel who succeeds for a time and is finally caught, but a really great criminal, the kind that appears once or twice, in a century, a man with immense power and intelligence."

"Like Vautrin in Napoleon's day?"

"Vautrin was a brilliant adventurer; he made millions with his swindling schemes, but he had no stability, no big purpose, and he finally came to grief. There have been greater criminals than Vautrin, men whose crimes have brought them everything—fortune, social position, political supremacy—and who have never been found out."

"Do you really think so?"

Coquenil nodded. "There have been a few like that with master minds, a very few; I have documents to prove it"—he pointed to his bookcases; "but we haven't time for that. Come back to my question: Suppose you were such a criminal, and suppose there was one person in this city who was thwarting your purposes, perhaps jeopardizing your safety. What would you naturally do?"

"I'd try to get rid of him."

"Exactly." Coquenil paused, and then, leaning closer to his friend, he said with extraordinary earnestness: "Lucien, for over two years some one has been trying to get rid of me!"

"The devil!" started Pougeot. "How long have you known this?"

"Only to-day," frowned the detective. "I ought to have known it long ago."

"Hm! Aren't you building a good deal on that dream?"

"The dream? Heavens, man," snapped Coquenil, "I'm building nothing on the dream and nothing on the girl. She simply brought together two facts that belong together. Why she did it doesn't matter; she did it, and my reason did the rest. There is a connection between this Rio Janeiro offer and my discharge from the force. I know it. I'll show you other links in the chain. Three times in the past two years I have received offers of business positions away from Paris, tempting offers. Notice that—business positions away from Paris! Some one has extraordinary reasons for wanting me out of this city and out of detective work."

"And you think this 'some one' was responsible for your discharge from the force?"

"I tell you I know it. M. Giroux, the chief at that time, was distressed at the order, he told me so himself; he said it came from higher up."

The commissary raised incredulous eyebrows. "You mean that Paris has a criminal able to overrule the wishes of a chief of police?"

"Is that harder than to influence the Brazilian Government? Do you think Rio Janeiro offered me a hundred thousand francs a year just for my beautiful eyes?"

"You're a great detective."

"A great detective repudiated by his own city. That's another point: why should the police department discharge me two years ago and recommend me now to a foreign city? Don't you see the same hand behind it all?"

M. Pougeot stroked his gray mustache in puzzled meditation. "It's queer," he muttered; "but——"

In spite of himself the commissary was impressed.

After all, he had seen strange things in his life, and, better than anyone, he had reason to respect the insight of this marvelous mind.

"Then the gist of it is," he resumed uneasily, "you think some great crime is preparing?"

"Don't you?" asked Coquenil abruptly.

"Why—er—" hesitated the Other.

"Look at the facts again. Some one wants me off the detective force, out of France. Why? There can be only one reason—because I have been successful in unraveling intricate crimes, more successful than other men on the force. Is that saying too much?"

The commissary replied impatiently: "It's conceded that you are the most skillful detective in France; but you're off the force already. So why should this person send you to Brazil?"

M. Paul thought a moment. "I've considered that. It is because this crime will be of so startling and unusual a character that it must attract my attention if I am here. And if it attracts my attention as a great criminal problem, it is certain that I will try to solve it, whether on the force or off it."

"Well answered!" approved the other; he was coming gradually under the spell of Coquenil's conviction. "And when—when do you think this crime may be committed?"

"Who can say? There must be great urgency to account for their insisting that I sail to-morrow. Ah, you didn't know that? Yes, even now, at this very moment, I am supposed to be on the steamer train, for the boat goes out early in the morning before the Paris papers can reach Cherbourg."

M. Pougeot started up, his eyes widening. "What!" he cried. "You mean that—that possibly—to-night?"

As he spoke a sudden flash of light came in through the garden window, followed by a resounding peal of thunder. The brilliant sunset had been followed by a violent storm.

Coquenil paid no heed to this, but answered quietly: "I mean that a great fight is ahead, and I shall be in it. Somebody is playing for enormous stakes, somebody who disposes of fortune and power and will stop at nothing, somebody who will certainly crush me unless I crush him. It will be a great case, Lucien, my greatest case, perhaps my last case." He stopped and looked intently at his mother's picture, while his lips moved inaudibly.

"Ugh!" exclaimed the commissary. "You've cast a spell over me. Come, come, Paul, it may be only a fancy!"

But Coquenil sat still, his eyes fixed on his mother's face. And then came one of the strange coincidences of this extraordinary case. On the silence of this room, with its tension of overwrought emotion, broke the sharp summons of the telephone.

"My God!" shivered the commissary. "What is that?" Both men sat motionless, their eyes fixed on the ominous instrument.

Again came the call, this time more strident and commanding. M. Pougeot aroused himself with an effort. "We're acting like children," he muttered. "It's nothing. I told them at the office to ring me up about nine." And he put the receiver to his ear. "Yes, this is M. Pougeot.... What?... The Ansonia?... You say he's shot?... In a private dining room?... Dead?... Quel malheur!"... Then he gave quick orders: "Send Papa Tignol over with a doctor and three or four agents. Close the restaurant. Don't let anyone go in or out. Don't let anyone leave the banquet room. I'll be there in twenty minutes. Good-by."

He put the receiver down, and turning, white-faced, said to his friend: "It has happened."

Coquenil glanced at his watch. "A quarter past nine. We must hurry." Then, flinging open a drawer in his desk: "I want this and—this. Come, the automobile is waiting."