THE events of the Versailles road left Grace Duvall in a high state of good humor. The plan she had suggested had been a success—at least so far as her own part in it was concerned. How Monsieur Lefevre had fared, she did not yet know. She looked down at the brown paper package she held in her hand, and ordered Valentin to drive to the Prefecture.

The day had been an eventful one. Immediately after breakfast Grace had gone to Mr. Stapleton's house and had a long interview with Mrs. Stapleton. That lady, apparently quite prostrated from worry and alarm over the fate of her son, received her in her boudoir, where she lay, a charming picture, upon a divan.

Grace had no more than entered the room, when she detected the odor of cigarette smoke, faint but unmistakable. She glanced at the table which stood beside the divan upon which Mrs. Stapleton lay. On it, a tiny porcelain ash receiver contained a fluffy mass of gray-white ashes, and the half smoked remains of a cigarette. The tip, partly covered by the ashes, was of gold.

The girl engaged her hostess in a long conversation, quieting her fears, which seemed real enough, and predicting the early recovery of her boy. It was quite evident that Mrs. Stapleton was terribly nervous. No doubt this accounted for the cigarettes. Although Grace did not use them herself, she knew how their quieting effect on the nerves made them almost necessities, at times, to their devotees.

Presently she observed that Mrs. Stapleton held within her left hand, concealed beneath the folds of her kimono, a small pasteboard box, a box of cigarettes. Grace determined upon a bold move.

"May I have one of your cigarettes, Mrs. Stapleton?" she asked, in her sweetest manner. "I've forgotten to bring any with me—and—you know how it is."

Mrs. Stapleton's features relaxed into something approaching a smile. She had been lying there wondering whether she dared offer one to Grace, and thus be able to sooth her own overstrained nerves. She brought forth the box and extended it toward her visitor. Grace took one of the tiny cylinders and lit it. It was of the same make as the one she had secured in Alphonse Valentin's room!

She took her departure a little later, wondering greatly. The whole affair had begun to take on an air of baffling contradiction.

She spent the rest of the morning, and most of the afternoon, searching the houses near the point on the road to Versailles indicated by Valentin. With her were three men from the Prefect's office—silent, able men, in plain clothes, who pretended to be keepers from the Jardin des Plantes, in search of a dangerous cobra, which was supposed to have escaped from its cage the night before.

The terrified householders threw open their doors with unassumed alacrity. The suggestion of a deadly reptile lurking in their gardens was a veritable open sesame. Yet no traces of the missing boy were found, and, more remarkable still, Grace was unable to identify any of the many gardens as the one in which she had seen the child playing with the spaniel. This disappointed her greatly. She knew well that, if Valentin was telling the truth, the garden was here; yet, although they visited every house within a quarter of a mile, they were unable to locate it. She remembered now that in her agitation, her eager examination of the child, she had not fixed upon her mind any salient point in the garden itself. All that she remembered was a bit of grass, a gravel walk, and the child playing with the dog. A dozen of the little enclosures presented similar features. She returned to the prefecture, baffled.

"The fellow is undoubtedly lying," had been Monsieur Lefevre's comment. "He is trying to throw you off the track, in order to protect the nurse, and possibly Mrs. Stapleton as well. I should not be surprised to find that the boy's mother is the guilty person."

Grace did not agree with him; so she said nothing. In spite of the fact that Mrs. Stapleton used cigarettes similar to those which seemed in some queer way to be at the bottom of the mystery, she had an intuitive feeling that the grief which the banker's wife showed was entirely real.

At half past seven, Grace left the prefecture in a high-powered car, furnished by Monsieur Lefevre. Alphonse Valentin was at the wheel. In her hand she held a pocket electric searchlight, across the front of which had been affixed a circular bit of blue glass.

At ten minutes to eight she arrived at Versailles. She at once ordered Valentin to turn and drive back toward Paris at moderate speed. She did not take him into her confidence regarding what she proposed to do, but kept a keen watch for the car containing Mr. Stapleton.

Her plan had worked. Mr. Stapleton, seeing her signal, had tossed her the package of money—she only hoped that the other part of her plan had been carried out with equal success.

The other part of the plan had been this: Monsieur Lefevre, who in build and general appearance was not unlike Mr. Stapleton, was to follow the latter's car in a machine of the same make and general appearance. He was to be driven by a chauffeur made up to resemble FranÇois sufficiently to be mistaken for him in the dim light of early evening. He himself was to make such alterations in his appearance and dress as would enable him to pass, under a cursory examination, for Stapleton. In the bottom of the car two armed men lay concealed.

When the car containing Mr. Stapleton turned back toward Paris, after having unwittingly delivered the money to Grace, the Prefect would continue on toward Versailles. He would know that the car containing the kidnappers was still ahead of him; since, had it not been, it, instead of Grace's car, would have signaled Mr. Stapleton.

Grace had started out from Versailles especially early, convinced that the kidnappers would not leave there until eight, at least. In this assumption she was correct. The car containing the kidnappers was, at that moment, creeping toward Paris some two miles in her rear, looking everywhere for Mr. Stapleton.

The Prefect pursued his way toward Versailles in anxious expectancy. Each moment he thought to see the blue signal flash from the various cars which passed him. When it came, his men were to spring up, and at once bring the other car to a standstill by firing their guns, heavily charged with buckshot, at its wheels. A punctured tire, and the thing was done. His men, assisted by the chauffeur, would then overpower the occupants of the other car before they could realize what had happened. In it they hoped to find the child.

The plan was well conceived; but unfortunately it did not work. Whatever the reason, none of the cars which passed the Prefect on his way to Versailles displayed the telltale blue light. All seemed but peaceable automobilists, intent on reaching Paris and its restaurants as quickly as possible. Had his disguise been penetrated? He could not believe it. He returned to the Prefecture in great disgust, wondering in what way matters had gone wrong.

Grace was waiting for him, an eager smile on her face. "Here is the money," she said, placing the package on his desk. "Did you get the men?"

"No." The Prefect flung himself into a chair. "They did not signal."

"But why, I wonder?" The failure of her plan was extremely annoying.

"I can think of but one reason. There must have been some way in which these fellows knew the Stapleton car when they approached it—some signal, perhaps, that I was unable to give."

"But no such signal was mentioned in the instructions I brought to Mr. Stapleton. He gave none, as we approached him."

"Did you observe anything peculiar about the appearance of his car, anything that might have served as a clue to enable these fellows to recognize it, even in the dark, with certainty?"

Grace thought a moment, then her face fell. "There was one thing that I noticed as Mr. Stapleton's car came up to us; but I am afraid I failed to realize its significance at the time."

"What was it?"

"The electric headlight on the side nearest to me was working very badly. In fact, it seemed to be almost out. The other was burning brilliantly."

The Prefect sprang to his feet. "SacrÉ!" he exclaimed. "Of course. The thing is as plain as the nose on your face!"

"But who—"

"FranÇois! The fellow is in this thing up to his neck. He claims to have been asleep when the boy was stolen. He drives the car which brings you back, after your abduction. He, disguised, steals the box of cigarettes. He fixes the lights so that the kidnappers are advised, not only beyond any doubt that they are signaling the right car, but that all is safe—that Monsieur Stapleton has no detectives or members of the police hidden in his tonneau. The thing is perfectly clear. Believe me, my child, had there been anyone in that car with Mr. Stapleton, those lights would have both been burning with equal brightness, as mine were. They did not give me the signal, when they passed me, because the lights failed to tell them that all was well."

Grace looked up quickly. "Then, if that is true, FranÇois knew that Mr. Stapleton had thrown the money into the wrong car."

"Undoubtedly, and by this time, no doubt, his confederates know it as well. Naturally the child has not been delivered. We are just where we were before."

"You will arrest FranÇois at once, I suppose."

"No. It will be useless. By leaving him free, we may learn something. By locking him up, with no tangible evidence against him, we accomplish nothing at all."

"Then what do you advise?"

"You will return the money to Mr. Stapleton at once. You can tell him, if you wish, how it came into your possession. He will be furious, of course; but he must understand that the capture of these scoundrels is quite as important to the city of Paris as the recovery of his son. We have done our best, and failed. We must try again.""Richard was at the Porte de Versailles," remarked Grace, quietly. "He tried to stop my car."

"Yes. I saw him. He is coming here at once."

The girl rose, in nervous haste. "I must go, then. It would be most unwise to have him find me here."

There was a quick knock at the door. The Prefect rose, and opened it; then turned to Grace with a grim smile. "Your husband is waiting in the anteroom," he whispered.

"But—what shall I do?"

"Wait in here." Monsieur Lefevre opened the door which led to his private office. "You can hear everything quite plainly. From what you tell me, I should not be surprised if he insisted upon your arrest at once."

"It isn't fair to him. Poor Richard! I'm afraid he'll never forgive me for all this."

"Nonsense! You are engaged in a very laudable attempt to recover Mrs. Stapleton's child. So is he. Your interests are identical. Only," he paused with a significant smile, "from my standpoint, I should much prefer that the credit for the boy's recovery should belong to the police of Paris, of which you, for the time being, are one."

Richard Duvall came into the Prefect's office, somewhat ill at ease. The room, familiar to him because of the events of the past, reminded him forcibly of Grace—who had, indeed been upon his mind constantly for the past few days. It was here, in this very room, that she had first told him that she loved him—during the exciting pursuit of Victor Girard, and the million francs. He gazed about at its familiar aspect, and sighed.

"Sit down, my dear Duvall," said the Prefect, shaking hands with him warmly. "What, may I ask, brings you to Paris, at the cost of interrupting your honeymoon? I had supposed that nothing could be of sufficient importance for that. In fact, had I known you would consider it for a moment, I should have cabled to you, to give me your assistance in a most trying case."

"What case, Monsieur?"

"The mysterious kidnapping of the child of Monsieur Stapleton."

"It is that very case that brings me to Paris. I am in Mr. Stapleton's employ."

Monsieur Lefevre affected to be greatly surprised. "Is it possible, mon ami? That is bad news indeed. This fellow Stapleton no longer has confidence in my office. He retains you to do that which he believes I shall fail to do. I am sorry, my dear Duvall, that we are on opposite sides of the fence."

"But, Monsieur, I did not know that you wanted me. Mr. Stapleton is an old friend. I could not refuse to come to his assistance."

Lefevre's eyes twinkled. "Have you made any progress, then, my friend?"

"Yes. Tonight I put in operation a plan whereby I might identify an automobile containing the kidnappers, into which Mr. Stapleton had been directed to throw a package containing one hundred thousand dollars."

"Indeed. You interest me. And did you succeed in identifying it?"

"I did. I stopped the car, at the Porte de Versailles. I knew it to be the one into which the money had been thrown. The car was driven by a man named Alphonse Valentin, whom I have every reason to suspect is concerned in this affair. Its only other occupant was a woman—whom I met last night in Valentin's rooms, and who brought Mr. Stapleton a message from the kidnappers. This woman is, I believe, at the bottom of the whole thing."

"Indeed. And did you arrest her?"

"No. She claims to be an agent of your office. Vernet, who was at the gates at my request, refused to place her and her companion under arrest. She got away with Mr. Stapleton's money. I believe, Monsieur Lefevre, that you are being made a fool of by a member of your own staff."

The Prefect leaned over, and picked up the package containing the money which lay upon his desk. "I do not agree with you, my friend. Here is Monsieur Stapleton's money."

Duvall started back in his chair, amazed. "Good Lord, Chief, am I losing my senses? What is this affair, anyway, a joke?"

"Far from it, Monsieur Duvall. The criminals are still at large. The boy is in their hands. We must recover him."

"But—this money—"

"I arranged to get it, in order to prevent Monsieur Stapleton from making a fool of himself. I wish to capture these men—not to let them blackmail him out of half a million francs."

"Had you not interfered, Monsieur Lefevre, they would have been in my hands, by now. I would have had them safely the moment they attempted to enter Paris. I knew their car."

The Prefect was filled with curiosity. "How?" he asked.

"My means of a device with which Mr. Stapleton's car was equipped, the body of the one into which he threw the money was spattered with red paint. I could have identified it anywhere."

"My dear Duvall! I feel that I should beg your pardon. Your plan was cleverness itself, and I will admit that, had I not interfered, you would in all probability have captured these men. I did not know what you had done, of course. Yet in their escape I have one consolation. It would have been extremely distasteful to me, to have had Mr. Stapleton boast that a private detective in his employ had succeeded, where the police of Paris had failed."

"Then it would appear, Monsieur," said Duvall somewhat stiffly, "that we are, in this matter at least, in opposition."

"Let us rather say, my friend, in competition." He placed his hand on Duvall's shoulder. "You must not blame me, if I feel a pride in my office. When you were working for the city of Paris, you, too, felt that pride. I am truly sorry that I have not the benefit of your services now. However, I think you will admit, mon ami, that the young woman who is handing this case is no mean adversary." The Prefect regarded the detective with a quizzical smile, behind which his eyes twinkled merrily.

"Who is this woman?" asked Duvall, quickly.

"Her name is—Goncourt—Estelle Goncourt."

"A Frenchwoman?"

"Partly. I believe her mother was English." The twinkle in his eye spread—he smiled upon the detective with expansive good humor. "Why do you ask?"

"You will think it strange, perhaps, Monsieur Lefevre, but when I first saw Miss Goncourt, she reminded me strongly of my wife."

"Of Grace?"

"Yes. Have you not observed it?"

"Now that you speak of it, perhaps there is something similar in the manner—the carriage. But your wife, my dear Duvall, is a blonde, while Mademoiselle Goncourt is decidedly a brunette."

"Yes. Of course. But, nevertheless, the resemblance is striking." He rose to go. "I hope, Monsieur, that this kidnapped boy may be restored to his father very soon. I am anxious to return to America."

"What! Leave Paris so quickly? My dear Duvall, I thought you Americans loved our city so well, that you never wanted to leave it."

"Paris is all right, Monsieur; but," he laughed heartily, "I must get back to my wife and my farm. I was forced to leave in the very middle of my spring plowing."

The Prefect roared. "You—a farmer! Mon Dieu! How droll! Potatoes, I suppose, and chickens, and dogs, and pigs—"

"Exactly—and, believe me, Monsieur, they are more to my liking, than all the gaieties of Paris. Some day you must make us a visit, and see for yourself." He turned toward the door.

"I shall, Duvall, I shall. But first we have to find this boy. What do you propose to do next?"

Duvall smiled. "What do you?" he retorted.

"A bottle of champagne, my friend, and a dinner at the CafÉ Royale, that we find the child before you do!"

"Done! Now I'll be off. Good night."

The Prefect was still laughing when Grace peeped in from the private office, to find that Richard had gone. "I think it's a shame to treat him so," she said. "The poor fellow! And he would have gotten the kidnappers, if we hadn't interfered."

Monsieur Lefevre picked up the package containing Mr. Stapleton's money and placed it carefully in his safe. "Tomorrow you must return it to him," he said. "And then, I would suggest that you keep a close watch upon Mrs. Stapleton. My men have not been keeping her under surveillance. We have had no suspicions of her whatever. She may, if she is concerned in this matter, be imprudent enough to attempt to visit the child."

"And if not?"

"Then watch FranÇois. If nothing comes of your efforts in either direction, I fear that we must wait for the kidnappers to make the next move. Of course there is Valentin—"

"Valentin is innocent."

"How do you know that?"

"I have watched him. He did everything in his power, tonight, to assist me. Had he been in league with the kidnappers, he could, after he knew that I had secured the money, easily have driven the car to some quiet spot and taken it from me. I was waiting for some such move; but he, as you know, did not attempt it. I am sure that he is doing his best to assist us."

"In that event, perhaps you can induce him to tell you the secret of the box of cigarettes. I feel sure that this knowledge would go far toward solving the entire affair."

"I'll have a talk with him tomorrow."

"Good! And now, if you are ready, we will return home at once."

"Dear old Richard!" said Grace, as the Prefect helped her into his automobile. "I wish I were with him tonight."

Lefevre smiled, and patted her hand. "So do I, my dear. But, remember, you have only to find Mr. Stapleton's child, and you can return to your chickens and your cows with the knowledge that you have done both his parents and myself an inestimable service."