The Emperor retired while the search of the grounds was being conducted, and Piexoto and I were escorted to another room upon the ground floor and locked in. There were two unbarred windows looking upon the grounds, but a sentry was posted at each of these, and as we were still hand-cuffed, our escape was impossible.

For a time my companion did nothing but curse Paola in the most hearty and diversified manner, and I made no effort to stop him. But finally this amusement grew monotonous even to its author, and he asked me how I had allowed myself to be captured.

I therefore related my adventures, but said nothing about the ring.

“I have always suspected Paola,” he told me, “and often warned Dom Miguel against him. The man’s very nature is frivolous. He could not be expected to keep faith. Yet it is surprising he did not choose to betray the Emperor, rather than us; for the Revolution is too powerful and too far advanced to be quelled by the arrest of a few of its leaders.”

“But what of Fonseca?” I asked curiously. “Why was he not arrested also? Why was not his name mentioned to the Emperor?”

“I confess the fact puzzles me,” returned Piexoto, thoughtfully. “Fonseca is even more compromised than I am myself, and unless he had a secret understanding with Paola, and purchased immunity, I cannot account for his escaping arrest.”

“But the general will not forsake the cause, I am sure,” I said, earnestly. “And it seems that Senhor Bastro, also, has succeeded in eluding arrest. Therefore, should the royalists fail to find the key to the vault, all may yet be well, in spite of Paola’s treachery.”

“There is another perplexing matter,” returned Piexoto, pacing the room in deep thought. “Miguel de Pintra never told me the vault was sheathed with nitro-glycerine. Did you know it?”

“Yes,” I answered. “But the secret was revealed to me by Lesba Paola, the Minister’s sister.”

“I can scarcely believe it, nevertheless,” he resumed. “Yet what object could the traitor have in preventing their reaching the records, unless he knew the attempt to drill through the walls would destroy us all—himself included?”

“Perhaps he has fear that the records would incriminate him with the Emperor,” I suggested.

“Bah! He has made his terms, evidently. That he worked faithfully in our interests for a time is quite believable; but either the Emperor’s bribes were too tempting or he lost faith in the Cause.”

I was about to reply when the door opened to admit Paola. Piexoto paused in his walk to glare at the Minister, and I was myself no less surprised at the inopportune visit.

But Paola, with the old, smirking smile upon his face that nothing ever seemed to banish, nodded pleasantly at us and sat down in an easy-chair. He rolled a cigarette and carefully lighted it before he addressed us.

“Senhors, you are about to denounce me as a traitor to the Cause,” said he; “but you may both spare your words. Before the Cause existed I was Minister to the Emperor. A policeman walks in devious paths. If I am true to the oath I gave the Emperor, how dare you, Floriano Piexoto, who have violated yours, condemn me?”

“I don’t,” answered the other. “It is absurd to condemn a man like you. Treachery is written on every line of your false face. My only regret is that I did not kill you long ago.”

“Yet the chief, Dom Miguel de Pintra, trusted me,” remarked Paola, in a musing tone, at the same time flicking the ash from his cigarette with a deliberate gesture. “He was, it seems, the only one.”

“Not so,” said I, angry at his insolent bearing. “Your sister, sir, had faith in you.”

He looked at me with a quizzical expression, and laughed. I had ventured the remark in an endeavor to pierce his shield of conceit and indifference. But it seemed that even Lesba’s misplaced confidence failed to shame him, for at that moment the girl’s loyalty to the Cause seemed to me beyond a doubt.

“My sister was, I believe, an ardent republican. Poor little girl! How could she judge the merits of a political controversy? But there, senhors, let us have done with chidings. I am come for the key.”

Piexoto and I stared at each other aghast. The key! Could the Minister suspect either of us of possessing it?

“Quite prettily acted, gentlemen,” he resumed, “but it is useless to oppose my request. I suppose our friend Harcliffe has passed it on to you, senhor? No? Then he must have it on his person.”

“Are you mad?” I asked, with well-assumed contempt.

“No; but the Mexican is. I have just left his room, and he raves perpetually of a ring he has given to Robert Harcliffe, of New Orleans. A ring that must be restored to him on demand.”

“He raves,” said I, coolly, although my heart was beating wildly.

“He does, indeed,” acknowledged Paola. “And he tells exactly where the ring was placed—in the outer pocket of your jacket. Will you pardon me, senhor, if I prove the truth of his assertion?”

He rose and advanced to me with a soft, stealthy tread, and I backed away until I stood fairly against the wall, vainly endeavoring to find some way to circumvent him.

“Hold!” cried a clear voice, and as Paola swung around upon his heel I saw beyond him the form of Valcour outlined by the dark doorway.

“You were doubtless about to search the prisoner, senhor,” said the spy, calmly, as he approached us. “I have myself just come from the Mexican’s room and heard his ravings. But the task must be mine, since the Emperor has placed the search for the key in my hands.”

Paola turned with a slight shrug and resumed his seat.

“I have searched the prisoner already,” he announced, “but failed to find the ring. Doubtless he has passed it to Piexoto, or secreted it. Or, it may be, the Mexican’s words are mere ravings.”

The detective hesitated.

“Who is this Mexican, Senhor Paola?” he asked.

“Frankly, I do not know. Not a conspirator, I am sure, and evidently not a royalist.”

“Then how came he to know of the existence of the ring?”

“A mystery, my dear Valcour. Have you yet identified the man this Mexican murdered?”

“Not yet.”

“I myself have not had a good look at the body. If you will take me to him I will endeavor to locate the fellow. It was doubtless he who murdered Madam Izabel.”

As he spoke he rose and walked quietly toward the door, as if he expected Valcour to follow. But the spy, suddenly suspicious, cast a shrewd glance at me and replied:

“One moment, Senhor Paola. I must satisfy myself that neither Harcliffe nor Piexoto has the ring, in order that I may report to the Emperor.”

“As you like,” returned the Minister, indifferently, and resumed his chair.

Valcour came straight to my side, thrust his hand within my pocket, and drew out the ring.

“Ah!” he cried, his face lighting with joy, “your search must have been a careless one, my dear Paola! Here is news for the Emperor, at last.”

He hurried from the room, and Paola, still smiling, rose and faced us.

“It is a great pity,” said he, pleasantly, with his eyes on my face, “that God permits any man to be a fool.”

Before I could reply he had followed Valcour from the room, and Piexoto, regarding me with a sullen frown, exclaimed:

“I can say amen to that! Why did you not tell me you had the ring?”

I did not reply. The taunts and the loss of the ring had dazed me and I sank into a chair and covered my eyes with my hands.

Pacing the room with furious energy, Piexoto growled a string of laments and reproaches into my unwilling ears.

“My poor comrades! It is their death-warrant. These records will condemn to punishment half the great families of Brazil. And now when the battle is almost won, to have them fall into the Emperor’s hands. Thank God, de Pintra is dead! This blow would be worse to him than death itself.”

“However,” said I, somewhat recovering myself, “we shall now secure his body from that grim vault. That is one satisfaction, at least.”

He did not see fit to reply to this, but paced the floor in as great agitation as before.

Captain de Souza entered with two of his guards.

“The Emperor commands you to unlock the vault,” he said to me. “Be good enough to follow, senhor. And Senhor Piexoto is also requested to be present.”

“Tell the Emperor I refuse to unlock the vault,” I returned, firmly.

“And why?” demanded Piexoto, scornfully. “It is merely a question of time, now that they have the key, when they will find the right indentation in the door.”

“True,” I answered. Then, to the captain: “Lead on, I will follow.”

They escorted us to the library and down the winding stair until we stood in the well-known chamber at the end of the passage. The outer door of the vault lay open, displaying the steel surface of the inner door, with its countless indentations.

The Emperor and his secretary, together with Paola and Valcour, were awaiting us. The latter handed me the ring.

“His Majesty commands you to open the door, senhor Americano,” he said.

“I believe the Minister of Police designed this vault. Let him open it himself,” I replied, my resolution halting at the thought of what the open door would reveal.

“Yes, I designed it,” said the Minister, “but I did not execute the work. Doubtless in time I could open the door; but the Emperor is impatient.”

I saw that further resistance was useless. Bending over, I fitted the stone of the ring into the proper indentation, and shot the bolts. The great door was swung upward, a whiff of the damp, confined air entered my nostrils and made me shiver.

Reaching my hand within the vault I turned the switch that threw on the electric light, and then withdrew that the others might enter.

But no one moved. The light illuminated the full interior of the great vault, and every eye gazed eagerly within.

Valcour uttered a groan of baffled rage; Piexoto swore horribly in a scarcely audible tone, and the Minister of Police laughed.

“Good God!” cried the Emperor, with staring eyeballs, “the vault is empty!”