When Jennie returned to Vienna, and was once more installed in her luxurious rooms at the Palace Steinheimer, she received in due time a copy of the Daily Bugle, sent to her under cover as a registered letter. The girl could not complain that the editor had failed to make the most of the news she had sent him. As she opened out the paper she saw the great black headlines that extended across two columns, and the news itself dated not from Venice, but from Vienna, was in type much larger than that ordinarily used in the paper, and was double-leaded. The headings were startling enough:--

PHANTOM GOLD.

THE MOST GIGANTIC ROBBERY OF MODERN TIMES.

THE AUSTRIAN WAR CHEST DYNAMITED.

TWENTY MILLION POUNDS IN COIN LOOTED.

APPALLING DISASTER AT THE TREASURY IN VIENNA.

FOUR MEN KILLED, AND SIXTEEN OTHERS MORE OR LESS SERIOUSLY INJURED.

"Dear me!" the Princess cried, peering over Jennie's shoulder at these amazing headings, "how like home that looks. The Bugle doesn't at all resemble a London journal; it reminds me of a Chicago paper's account of a baseball match; a baseball match when Chicago was winning, of course, and when Anson had lined out the ball from the plate to the lake front, and brought three men in on a home run at a critical point in the game."

"Good gracious!" cried Jennie, "what language are you speaking? Is it slang, or some foreign tongue?"

"It is pure Chicagoese, Jennie, into which I occasionally lapse even here in prim Vienna. I would like to see a good baseball match, with the Chicago nine going strong. Let us abandon this effete monarchy, Jennie, and pay a visit to America."

"I'll go with pleasure if you will tell me first who robbed the war chest. If you can place your dainty forefinger on the spot that conceals two hundred million florins in gold, I'll go anywhere with you."

"Oh, yes, that reminds me. I spoke to my husband this morning, and asked him if he could get you enrolled as a special detective, and he said there would be some difficulty in obtaining such an appointment for a woman. Would you have any objection to dressing up as a nice young man, Jennie?"

"I would very much rather not; I hope you didn't suggest that to the Prince."

The Princess laughed merrily and shook her head.

"No, I told him that I believed that you would solve the mystery if anyone could, and, remembering what you had done in that affair of my diamonds, my husband has the greatest faith in your powers as an investigator; but he fears the authorities here will be reluctant to allow a woman to have any part in the search. They have very old-fashioned ideas about women in Austria, and think her proper place is presiding over a tea-table."

"Well, if they only knew it," said Jennie archly, "some things have been discovered over a teacup within our own memories."

"That is quite true," replied the Princess, "but we can hardly give the incident as a recommendation to the Austrian authorities. By the way, have you noticed that no paper in Vienna has said a single word about the robbery of the war chest?"

"It must have been telegraphed here very promptly from London, and yet they do not even deny it, which is the usual way of meeting the truth."

While they were talking, a message came from his Highness, asking if he might take the liberty of breaking in upon their conference. A few moments after, the Prince himself entered the apartment and bowed with courtly deference to the two ladies.

"I have succeeded," he said, "beyond my expectations. It seems that a newspaper in London has published an account of the whole affair, and the police, who were at their wits end before, are even more flustered now that the account of the robbery has been made public. By the way, how did you learn anything about this robbery? It did not strike me at the time you spoke about Miss Baxter's commission this morning, but I have been wondering ever since."

"Jennie received a paper from London," said the Princess hurriedly, "which said the war chest of Austria had been robbed of two hundred million florins, but there is nothing about it in the Vienna Press."

"No," replied the Prince; "nor is there likely to be. The robbery is now known to all the world except Austria, and I imagine nothing will be said about it here."

"Is there, then, any truth in the report?" asked the Princess innocently.

"Truth! It's all truth; that is just where the trouble is. There is little use of our denying it, because this London paper is evidently well informed, and to deny it we should have to publish something about the robbery itself, which we are not inclined to do. It is known, however, who the two correspondents of this London paper are, and I believe the police are going to make it so interesting for those two gentlemen that they will be glad to leave Vienna, for a time at least. Of course, nothing can be done openly, because Englishmen make such a fuss when their liberties are encroached upon. One of the young men has been lured across the frontier by a bogus telegram, and I think the authorities will see that he does not get back in a hurry; the other we expect to be rid of before long. Of course, we could expel him, but if we did, it would be thought that we had done so because he had found out the truth about the explosion."

"How did you learn of the explosion?" asked the Princess.

"Oh, I have known all about the affair ever since it happened."

The Princess gave Jennie a quick look, which said as plainly as words, "Here was the news that we wanted in our household, and we never suspected it." "Why didn't you tell me?" cried the Princess indignantly.

"Well, you see, my dear, you never took much interest in politics, and I did not think the news would have any attraction for you; besides," he added, with a smile, "we were all cautioned to keep the matter as secret as possible."

"And wonderfully well you have managed it!" exclaimed the Princess. "That shows what comes of trusting a secret to a lot of men; here it is, published to all the world."

"Not quite all the world my dear. As I have said, Austria will know nothing regarding it."

"The Princess tells me," said Jennie, "that you were kind enough to endeavour to get me permission to make some investigation into this mystery. Have you succeeded?"

"Yes, Miss Baxter, as I said, I have succeeded quite beyond my expectations, for the lady detective is comparatively an innovation in Vienna. However, the truth is, the police are completely in a fog, and they are ready to welcome help from whatever quarter it comes. Here is a written permit from the very highest authority, which you do not need to use except in a case of emergency. Here is also an order from the Chief of Police, which will open for you every door in Vienna; and finally, here is a badge which you can pin on some not too conspicuous portion of your clothing. This badge, I understand, is rarely given out. It is partly civil and partly military. You can show it to any guard, who will, on seeing it, give you the right-of-way. In case he does not, appeal to his superior officer, and allow him to read your police permit. Should that fail, then play your trump card, which is this highly important document. The Director of the Police, who is a very shrewd man, seemed anxious to make your acquaintance before you began your investigation. He asked me if you would call upon him, but seemed taken aback when I told him you were my wife's friend and a guest at our house, so he suggested that you would in all probability wish first to see the scene of the explosion, and proposed that he should call here with his carriage and accompany you to the Treasury. He wished to know if four o'clock in the afternoon would suit your convenience!"

"Oh, yes!" replied Jennie. "I am eager to begin at once, and, of course, I shall be much obliged to him if he will act as my guide in the vaults of the Treasury, and tell me how much they have already discovered."

"You must not expect much information from the police--in fact, I doubt if they have discovered anything. Still, if they have, they are more than likely to keep it to themselves; and I imagine they will hold a pretty close watch on you, being more anxious to learn what you discover, and thus take the credit if they can, than to furnish you with any knowledge of the affair they may happen to possess."

"That is quite natural, and only what one has a right to expect. I don't wish to rob the police of whatever repute there is to be gained from this investigation, and I am quite willing to turn over to them any clues I may happen to chance upon."

"Well, if you can convince the Director of that, you will have all the assistance he can give you. It wouldn't be bad tactics to let him know that you are acting merely in an amateur way, and that you have no desire to rob the police of their glory when it comes to the solving of the problem." Promptly at four o'clock the Director of the Police put in an appearance at the Palace Steinheimer. He appeared to be a most obsequious, highly decorated old gentleman, in a very resplendent uniform, and he could hardly conceal his surprise at learning that the lady detective was a woman so young and so pretty. Charmed as he was to find himself in the company of one so engaging, it was nevertheless evident to Jennie that he placed no very high estimate on the assistance she might be able to give in solving the mystery of the Treasury. This trend of mind, she thought, had its advantages, for the Director would be less loth to give her full particulars of what had already been accomplished by the police.

Jennie accompanied the Director to that extensive mass of buildings of which the Treasury forms a part. The carriage drew up at a doorway, and here the Director and his companion got out. He led the way into the edifice, then, descending a stair, entered an arched corridor, at the door of which two soldiers stood on guard, who saluted as the Chief passed them.

"Does this lead to the room where the explosion took place?" asked Jennie. "Yes." "And is this the only entrance?" "The only entrance, madame." "Were the men on guard in this doorway injured by the explosion?" "Yes. They were not seriously injured, but were rendered incapable for a time of attending to their duties." "Then a person could have escaped without their seeing him?" "A whole regiment of persons might have escaped. You will understand the situation exactly if I compare this corridor to a long cannon, the room at the end being the breech-loading chamber. Two guards were inside the room, and two others stood outside the door that communicated with this corridor. These four men were killed instantly. Of the guards inside the room not a vestige has been found. The door, one of the strongest that can be made, somewhat similar to the door of a safe, was flung outward and crushed to the floor the two guards who stood outside it in the corridor. Between the chamber in which the chest lay and the outside entrance were sixteen men on guard. Every one of these was flung down, for the blast, if I may call it so, travelled through this straight corridor like the charge along the inside of the muzzle of a gun. The guards nearest the treasure chamber were, of course, the more seriously injured, but those further out did not escape the shock, and the door by which we entered this corridor, while not blown from its hinges, was nevertheless forced open, its strong bolts snapping like matches. So when you see the great distance that intervened between the chamber and that door, you will have some idea of the force of the explosion."

"There is no exit, then, from the treasure chamber except along this corridor?"

"No, madame. The walls at the outside of the chamber are of enormous strength, because, of course, it was expected that if an attempt at robbery were ever made, it would be made from the outside, and it is scarcely possible that even the most expert of thieves could succeed in passing two guards at the door, sixteen officers and soldiers along the corridor, two outside the Treasury door, and two in the chamber itself. Such a large number of soldiers were kept here so that any attempt at bribery would be impossible. Among such a number one or two were sure to be incorruptible, and the guards were constantly changed. Seldom was either officer or man twice on duty here during the month. With such a large amount at stake every precaution was taken."

"Are there any rooms at the right or left of this corridor in which the thieves could have concealed themselves while they fired the mine?"

"No, the corridor leads to the treasure chamber alone."

"Then," said Jennie, "I can't see how it was possible for a number of men to have made away with the treasure in such circumstances as exist here."

"Nevertheless, my dear young lady, the treasure is gone. We think that the mine was laid with the connivance of one or more officers on duty here. You see the amount at stake was so large that a share of it would tempt any nine human beings out of any ten. Our theory is that the train was laid, possibly electric wires being used, which would be unnoticed along the edge of the corridor, and that the bribed officer exploded the dynamite by bringing the ends of the wires into contact. We think the explosion was a great deal more severe than was anticipated. Probably, it was expected that the shock would break a hole from the treasure chamber to the street, but so strong were the walls that no impression was made upon them, and a cabman who was driving past at the time heard nothing of the sound of the explosion, though he felt a trembling of the ground, and thought for a moment there had been a shock of earthquake."

"You think, then, that the thieves were outside?"

"That seems the only possible opinion to hold."

"The outside doors were locked and bolted, of course?"

"Oh, certainly; but if they had a confederate or two in the large hallway upstairs, these traitors would see to it that there was no trouble about getting in. Once inside the large hallway, with guards stunned by the shock, the way to the treasure chamber was absolutely clear."

"There were sentries outside the building, I suppose?"

"Yes."

"Did they see any vehicle driving near the Treasury?"

"No, except the cab I spoke of, and the driver has accounted satisfactorily for his time that night. The absence of any conveyance is the strange part of it; and, moreover, the sentries, although pacing outside the walls of this building, heard nothing of the concussion beyond a low rumble, and those who thought of the matter at all imagined an explosion had occurred in some distant part of the city."

"Then the outside doors in the large hall above were not blown open?"

"No; the officer reports that they were locked and bolted when he examined them, which was some minutes, of course, after the disaster had taken place; for he, the officer in charge, had been thrown down and stunned, seemingly by the concussion of air which took place."

As Jennie walked down the corridor, she saw more and more of the evidences of the convulsion. The thick iron-bound door lay where it had fallen, and it had not been moved since it was lifted to get the two men from under it. Its ponderous hinges were twisted as if they had been made of glue, and its massive bolts were snapped across like bits of glass. All along the corridor on the floor was a thick coating of dust and debris, finely powdered, growing deeper and deeper until they came to the entrance of the room. There was no window either in corridor or chamber, and the way was lit by candles held by soldiers who accompanied them. The scoria crunched under foot as they walked, and in the chamber itself great heaps of dust, sand and plaster, all pulverized into minute particles, lay in the corners of the room, piled up on one side higher than a man's head. There seemed to be tons of this debris, and, as Jennie looked up at the arched ceiling, resembling the roof of a vaulted dungeon, she saw that the stone itself had been ground to fine dust with the tremendous force of the blast.

"Where are the remnants of the treasure chest?" she asked.

The Director shook his head. "There are no remnants; not a vestige of it is to be found."

"Of what was it made?"

"We used to have an old treasure chest here made of oak, bound with iron; but some years ago, a new receptacle being needed, one was especially built of hardened steel, constructed on the modern principles of those burglar-proof and fire-proof safes."

"And do you mean to say that there is nothing left of this?"

"Nothing that we have been able to discover."

"Well, I have seen places where dynamite explosions have occurred, but I know of nothing to compare with this. I am sure that if dynamite has been used, or any explosive now generally obtainable, there would have been left, at least, some remnant of the safe. Hasn't this pile of rubbish been disturbed since the explosion?"

"Yes, it has been turned over; we made a search for the two men, but we found no trace of them."

"And you found no particles of iron or steel?"

"The heap throughout is just as you see it on the surface--a fine, almost impalpable dust. We had to exercise the greatest care in searching through it, for the moment it was disturbed with a shovel it filled the air with suffocating clouds. Of course we shall have it removed by-and-by, and carted away, but I considered it better to allow it to remain here until we had penetrated somewhat further into the mystery than we have already done."

Jennie stooped and picked up a handful from the heap, her action caused a mist to rise in the air that made them both choke and cough, and yet she was instantly struck by the fact that her handful seemed inordinately heavy for its bulk.

"May I take some of this with me?" she asked.

"Of course," replied the Director. "I will have a packet of it put up for you."

"I would like to take it with me now," said Jennie. "I have curiosity to know exactly of what it is composed. Who is the Government analyst? or have you such an official?"

"Herr Feltz, in the Graubenstrasse, is a famous analytical chemist; you cannot do better than go to him."

"Do you think he knows anything about explosives?"

"I should suppose so, but if not, he will certainly be able to tell you who the best man is in that line."

The Director ordered one of the soldiers who accompanied him to find a small paper bag, and fill it with some dust from the treasure chamber. When this was done, he handed the package to Jennie, who said, "I shall go at once and see Herr Feltz."

"My carriage is at your disposal, madame."

"Oh, no, thank you, I do not wish to trouble you further. I am very much obliged to you for devoting so much time to me already. I shall take a fiacre."

"My carriage is at the door," persisted the Director, "and I will instruct the driver to take you directly to the shop of Herr Feltz; then no time will be lost, and I think if I am with you, you will be more sure of attention from the chemist, who is a very busy man."

Jennie saw the Director did not wish to let her out of his sight, and although she smiled at his suspicion, she answered politely,--

"It is very kind of you to take so much trouble and devote so much of your time to me. I shall be glad of your company if you are quite certain I am not keeping you from something more important."

"There is nothing more important than the investigation we have on hand," replied the Chief grimly.