After a few moments a short, stout, clean-shaven man with a round, pleasant face, and dressed in black, entered and bowed to his chief.

He carried his soft felt hat and cane in his hand, and seated himself at the invitation of Van Huffel.

"This is Inspector FrÉmy—Monsieur Edouard Royle, of Londres," exclaimed the Chef du SuretÉ, introducing us.

The detective, the most famous police officer in Belgium, who had been for years under Monsieur Hennion, in Paris, and had now transferred his services to Belgium, bowed and looked at me with his small, inquisitive eyes.

"Monsieur FrÉmy. This gentleman has called with regard to the case of Marie Bracq," said Van Huffel in French.

The detective was quickly interested.

"She is dead—been assassinated in London," his chief went on.

FrÉmy stared at the speaker in surprise, and the two men exchanged strange glances.

"Monsieur tells me that the man, Sir Digby Kemsley, wanted by Scotland Yard, is accused of the murder of Marie Bracq—and, further," added Van Huffel, "the accused has been here in Brussels quite recently."

"In Brussels?" echoed the round-faced man.

"Yes," I said. "He has letters addressed to the Poste Restante in the name of Bryant." And I spelt it as the detective carefully wrote down the name.

"He will not be difficult to find if he is still in Brussels," declared the inspector. "We had an inquiry from Scotland Yard asking if we had any report concerning Marie Bracq only this morning," he added.

"It was sent to you by my friend, Inspector Edwards, and whom I am assisting in this inquiry," I explained.

"You said that Marie Bracq was a friend of a lady friend of yours, M'sieur Royle," continued the Chef du SuretÉ. "Will you do us the favour and tell us all you know concerning the tragedy—how the young lady lost her life?"

"Ah! m'sieur," I replied, "I fear I cannot do that. How she was killed is still a mystery. Only within the past few hours have I been able to establish the dead girl's identity, and only then after narrowly escaping falling the victim of a most dastardly plot."

"Perhaps you will be good enough to make a statement of all you know, M'sieur Royle," urged the grey-haired little man; "and if we can be of any service in bringing the culprit to justice, you may rely upon us."

"But first, m'sieur, allow me to put observation upon the Poste Restante?" asked FrÉmy, rising and going to the telephone, where he got on to one of his subordinates, and gave him instructions in Flemish, a language I do not understand.

Then, when he returned to his chair, I began to briefly relate what I knew concerning Sir Digby, and what had occurred, as far as I knew, on that fatal night of the sixth of January.

I, of course, made no mention of the black suspicion cast upon the woman I loved, nor of the delivery of Digby's letter, my meeting with the woman Petre and its exciting results.

Yet had I not met that woman I should still have been in ignorance of the identity of the dead girl, and, besides, I would not have met the sallow-faced Ali, or been aware of his methods—those methods so strangely similar to that adopted when Sir Digby Kemsley lost his life in Peru.

The two police functionaries listened very attentively to my story without uttering a word.

I had spoken of the woman Petre as being an accomplice of the man who was a fugitive, whereupon FrÉmy asked:

"Do you suppose that the woman is with him?"

"She has, I believe, left England, and, therefore, in all probability, is with him."

"Are there any others of the gang—for there is, of course, a gang? Such people never act singly."

"Two other men, as far as I know. One, a young man, who acts as servant, and the other, a tall, copper-faced man with sleek black hair—probably a Peruvian native. They call him Ali, and he pretends he is a Hindu."

"A Hindu!" gasped the detective. "Why, I saw one talking to a rather stout Englishwoman at the Gare du Nord yesterday evening, just before the Orient Express left for the East!" He gave a quick description of both the man and the woman, and I at once said:

"Yes, that was certainly Ali, and the woman was Mrs. Petre!"

"They probably left by the Orient Express!" he cried, starting up, and crossing to his chief's table snatched up the orange-coloured official time table.

"Ah! yes," he exclaimed, after searching a few moments. "The Orient Express will reach Wels, in Austria, at 2.17, no time for a telegram to get through. No. The next stop is Vienna—the Westbahnhof—at 6. I will wire to the Commissary of Police to board the train, and if they are in it, to detain them."

"Excellent," remarked his chief, and, ringing a bell, a clerk appeared and took down the official telegram, giving the description of the woman and her accomplice.

"I suppose the fugitive Englishman is not with them?" suggested the Chef du SuretÉ.

"I did not see him at the station—or, at least, I did not recognise anyone answering to the description," replied the inspector; "but we may as well add his description in the telegram and ask for an immediate reply."

Thereupon the official description of Digby, as supplied to the Belgian police by Scotland Yard, was translated into French and placed in the message.

After the clerk had left with it, FrÉmy, standing near the window, exclaimed:

"Dieu! Had I but known who they were last night! But we may still get them. I will see the employÉe at the Poste Restante. This Monsieur Bryant, if he receives letters, may have given an address for them to be forwarded."

After a slight pause, during which time the two functionaries conversed in Flemish, I turned to Van Huffel, and said:

"I have related all I know, m'sieur; therefore, I beg of you to tell me something concerning the young person Marie Bracq. Was she a lady?"

"A lady!" he echoed with a laugh. "Most certainly—the daughter of one of the princely houses of Europe."

"What?" I gasped. "Tell me all about her!"

But the dry-as-dust little man shook his grey head and replied:

"I fear, m'sieur, in my position, I am not permitted to reveal secrets entrusted to me. And her identity is a secret—a great secret."

"But I have discovered her identity where our English police had failed!" I protested. "Besides, am I not assisting you?"

"Very greatly, and we are greatly indebted to you, M'sieur Royle," he replied, with exquisite politeness; "but it is not within my province as Chef du SuretÉ to tell you facts which have been revealed to me under pledge of secrecy."

"Perhaps M'sieur FrÉmy may be able to tell me some facts," I suggested. "Remember, I am greatly interested in the mysterious affair."

"From mere curiosity—eh?" asked Van Huffel with a smile.

"No, m'sieur," was my earnest reply. "Because the arrest and condemnation of the assassin of Marie Bracq means all the world to me."

"How?"

I hesitated for some moments, then, hoping to enlist his sympathy, I told him the truth.

"Upon the lady who is my promised wife rests a grave suspicion," I said, in a low, hard voice. "I decline to believe ill of her, or to think that she could be guilty of a crime, or——"

"Of the assassination of Marie Bracq?" interrupted Van Huffel. "Do you suspect that? Is there any question as to the guilt of the man Kemsley?" he asked quickly.

"No one has any suspicion of the lady in question," I said. "Only—only from certain facts within my knowledge and certain words which she herself has uttered, a terrible and horrible thought has seized me."

"That Marie Bracq was killed by her hand—eh? Ah, m'sieur, I quite understand," he said. "And you are seeking the truth—in order to clear the woman you love?"

"Exactly. That is the truth. That is why I am devoting all my time—all that I possess in order to solve the mystery and get at the actual truth."

FrÉmy glanced at his chief, then at me.

"Bien, m'sieur," exclaimed Van Huffel. "But there is no great necessity for you to know the actual identity of Marie Bracq. So long as you are able to remove the stigma from the lady in question, who is to be your wife, and to whom you are undoubtedly devoted, what matters whether the dead girl was the daughter of a prince or of a rag-picker? We will assist you in every degree in our power," he went on. "M'sieur FrÉmy will question the postal clerk, watch will be kept at the Poste Restante, at each of the railway stations, and in various other quarters, so that if any of the gang are in the city they cannot leave it without detection——"

"Except by automobile," I interrupted.

"Ah! I see m'sieur possesses forethought," he said with a smile. "Of course, they can easily hire an automobile and run to Namur, Ghent, or Antwerp—or even to one or other of the frontiers. But M'sieur FrÉmy is in touch with all persons who have motor-cars for hire. If they attempted to leave by car when once their descriptions are circulated, we should know in half an hour, while to cross the frontier by car would be impossible." Then, turning to the inspector, he said, "You will see that precautions are immediately taken that if they are here they cannot leave."

"The matter is in my hands, m'sieur," answered the great detective simply.

"Then m'sieur refuses to satisfy me as to the exact identity of Marie Bracq?" I asked Van Huffel in my most persuasive tone.

"A thousand regrets, m'sieur, but as I have already explained, I am compelled to regard the secret entrusted to me."

"I take it that her real name is not Marie Bracq?" I said, looking him in the face.

"You are correct. It is not."

"Is she a Belgian subject?" I asked.

"No, m'sieur, the lady is not."

"You said that a great sensation would be caused if the press knew the truth?"

"Yes. I ask you to do me the favour, and promise me absolute secrecy in this matter. If we are to be successful in the arrest of these individuals, then the press must know nothing—not a syllable. Do I have your promise, M'sieur Royle?"

"If you wish," I answered.

"And we on our part will assist you to clear this lady who is to be your wife—but upon one condition."

"And that is what?" I asked.

"That you do not seek to inquire into the real identity of the poor young lady who has lost her life—the lady known to you and others as Marie Bracq," he said, looking straight into my eyes very seriously.