"It's a composition of rubber," laughed Coquenil. "You slip it on over your own tooth. See?" and he put back the yellow fang.
"Extraordinary!" muttered Tignol. "Even now I hardly know you."
"Then I ought to fool the wood carver."
"Fool him? You would fool your own mother. That reminds me—" He rose as the train stopped.
"Yes, yes?" questioned M. Paul eagerly. "Tell me about my mother. Is she well? Is she worried? Did you give her all my messages? Have you a letter for me?"
Tignol smiled. "There's a devoted son! But the old lady wouldn't like you with those teeth. Eh, eh! Shades of Vidocq, what a make-up! We'd better get out! I'll tell you about my visit as we walk along."
"Where are you going?" asked the detective, as the old man led the way toward the Rue La Fontaine.
"Going to get the dog," answered Tignol.
"No, no," objected M. Paul. "I wouldn't have Cæsar see me like this. I have a room on the Rue Poussin; I'll go back there first and take off some of this."
"As you please," said Tignol, and he proceeded to give Coquenil the latest news of his mother, all good news, and a long letter from the old lady, full of love and wise counsels and prayers for her boy's safety.
"There's a woman for you!" murmured M. Paul, and the tenderness of his voice contrasted oddly with the ugliness of his disguise.
"Suppose I get the dog while you are changing?" suggested Tignol. "You know he's been clipped?"
"Poor Cæsar! Yes, get him. My room is across the street. Walk back and forth along here until I come down."
Half an hour later Coquenil reappeared almost his ordinary self, except that he wore neither mustache nor eyeglasses, and, instead of his usual neat dress he had put on the shabby black coat and the battered soft hat that he had worn in leaving the Hôtel des Étrangers.
"Ah, Cæsar! Old fellow!" he cried fondly as the dog rushed to meet him with barks of joy. "It's good to have a friend like that! Where is the man who cares so much? Or the woman either—except one?"
"There's one woman who seems to care a lot about this dog," remarked Tignol. "I mean the candle girl. Such a fuss as she made when I went to get him!"
M. Paul listened in surprise. "What did she do?"
"Do? She cried and carried on in a great way. She said something was going to happen to Cæsar; she didn't want me to take him."
"Strange!" muttered the other.
"I told her I was only taking him to you, and that you would bring him back to-night. When she had heard that she caught my two hands in hers and said I must tell you she wanted to see you very much. There's something on her mind or—or she's afraid of something."
Coquenil frowned and twisted his seal ring, then he changed it deliberately from the left hand to the right, as if with some intention.
"We'll never get to the bottom of this case," he muttered, "until we know the truth about that girl. Papa Tignol, I want you to go right back to Notre-Dame and keep an eye on her. If she is afraid of something, there's something to be afraid of, for she knows. Don't talk to her; just hang about the church until I come. Remember, we spend the night there."
"Sapristi, a night in a church!"
"It won't hurt you for once," smiled M. Paul. "There's a bed to sleep on, and a lot to talk about. You know we begin the great campaign to-morrow."
Tignol rubbed his hands in satisfaction. "The sooner the better." Then yielding to his growing curiosity: "Have you found out much?"
Coquenil's eyes twinkled. "You're dying to know what I've been doing these last five days, eh?"
"Nothing of the sort," said the old man testily. "If you want to leave me in the dark, all right, only if I'm to help in the work——"
"Of course, of course," broke in the other good-naturedly. "I was going to tell you to-night, but Bonneton will be with us, so—come, we'll stroll through the bois as far as Passy, and I'll give you the main points. Then you can take a cab."
Papa Tignol was enormously pleased at this mark of confidence, but he merely gave one of his jerky little nods and walked along solemnly beside his brilliant associate. In his loyalty for M. Paul this tough old veteran would have allowed himself to be cut into small pieces, but he would have spluttered and grumbled throughout the operation.
"Let's see," began Coquenil, as they entered the beautiful park, "I have five days to account for. Well, I spent two days in Paris and three in Brussels."
"Where the wood carver lives?"
"Exactly. I got his address from Papa Bonneton. I thought I'd look the man over in his home when he was not expecting me. And before I started I put in two days studying wood carving, watching the work and questioning the workmen until I knew more about it than an expert. I made up my mind that, when I saw this man with the long little finger, I must be able to decide whether he was a genuine wood carver—or—or something else."
"I see," admired Tignol. "Well?"
"As it turned out, I didn't find him, I haven't seen him yet. He was away on a trip when I got to Brussels, away on this trip that will bring him to Paris to-morrow, so I missed him and—it's just as well I did!"
"You got facts about him?"
"Yes, I got facts about him; not the kind of facts I expected to get, either. I saw the place where he boards, this Adolph Groener. In fact, I stopped there, and I talked to the woman who runs it, a sharp-eyed young widow with a smooth tongue; and I saw the place where he works; it's a wood-carving shop, all right, and I talked to the men there—two big strong fellows with jolly red faces, and—well—" he hesitated.
"Well?"
The detective crossed his arms and faced the old man with a grim, searching look.
"Papa Tignol," he said impressively, "they all tell a simple, straight story. His name is Adolf Groener, he does live in Brussels, he makes his living at wood carving, and the widow who runs the confounded boarding house knows all about this girl Alice."
Tignol rubbed his nose reflectively. "It was a long shot, anyway."
"What would you have done?" questioned the other sharply.
"Why," answered Tignol slowly, while his shrewd eyes twinkled, "I—I'd have cussed a little and—had a couple of drinks and—come back to Paris."
Coquenil sat silent frowning. "I wasn't much better. After that first day I was ready to drop the thing, I admit it, only I went for a walk that night—and there's a lot in walking. I wandered for hours through that nice little town of Brussels, in the crowd and then alone, and the more I thought the more I came back to the same idea, he can't be a wood carver!"
"You couldn't prove it, but you knew it," chuckled the old man.
Coquenil nodded. "So I kept on through the second day. I saw more people and asked more questions, then I saw the same people again and tried to trip them up, but I didn't get ahead an inch. Groener was a wood carver, and he stayed a wood carver."
"It began to look bad, eh?"
Coquenil stopped short and said earnestly: "Papa Tignol, when this case is over and forgotten, when this man has gone where he belongs, and I know where that is"—he brought his hand down sideways swiftly—"I shall have the lesson of this Brussels search cut on a block of stone and set in my study wall. Oh, I've learned the lesson before, but this drives it home, that the most important knowledge a detective can have is the knowledge he gets inside himself!"
Tignol had never seen M. Paul more deeply stirred. "Sacré matin!" he exclaimed. "Then you did find something?"
"Ah,