The stairs led us beneath the foundations of the house and terminated in a domed chamber constructed of stone and about ten feet in diameter.

In the floor of this chamber was a trapdoor, composed of many thicknesses of steel, and so heavy that it could be raised only by a stout iron windlass, the chain of which was welded to a ring in the door’s face.

Dom Miguel handed me the candle and began turning the windlass. Gradually but without noise the heavy door of metal rose, and disclosed a still more massive surface underneath.

This second plate, of highly burnished steel, was covered with many small indentations, of irregular formation. It was about three feet square and the curious indentations, each one of which had evidently been formed with great care, were scattered over every inch of the surface.

“Put out the light,” said de Pintra.

I obeyed, leaving us in total darkness.

Next moment, as I listened intently, I heard a slight grating noise, followed by a soft shooting of many bolts. Then a match flickered, and Dom Miguel held it to the wick and relighted the candle.

The second door had swung upward upon hinges, showing three iron steps that led into a vault below.

The chief descended and I followed; not, however, without a shuddering glance at the great door that stood suspended as if ready to crash down upon our heads and entomb us.

Just within the entrance an electric light, doubtless fed by a storage battery, was turned on, plainly illuminating the place.

I found the vault lined with thick plates of steel, riveted firmly together. In the center was a small table and two wooden stools. Shelves were ranged around the walls and upon them were books, papers, and vast sums of money, both in bank-notes and gold.

“Here,” said my companion, glancing proudly around him, “are our sinews of war; our records and funds and plans of operation. Should Dom Pedro’s agents gain access to this room they would hold in their hands the lives and fortunes of many of the noblest families in Brazil—and our conspiracy would be nipped in the bud. You may know how greatly I trust you when I say that even my daughter does not guess the existence of this vault. Only a few of the Secret Council have ever gained admittance here, and the secret of opening the inner door is known only to myself and one other—Francisco Paola.”

“Paola!” I exclaimed.

“Yes; it was he who conceived the idea of this vault; it was his genius that planned a door which defies any living man to open without a clear knowledge of its secret. Even he, its inventor, could not pass the door without my assistance; for although he understands the method, the means are in my possession. For this reason I alone am responsible for the safe-keeping of our records and treasure.”

“The air is close and musty,” said I, feeling oppressed in breathing.

He looked upward.

“A small pipe leads to the upper air, permitting foul vapors to escape,” said he; “but only through the open door is fresh air admitted. Perhaps there should be better ventilation, yet that is an unimportant matter, for I seldom remain long in this place. It is a store-house—a secret crypt—not a work-room. My custom has been to carry all our records and papers here each morning, after they have been in use, that they may be safe from seizure or prying eyes. But such trips are arduous, and I am not very strong. Therefore I will ask you to accompany me, hereafter.”

“That I shall do willingly,” I replied.

When we had passed through the door on our return the chief again extinguished the light while he manipulated the trap. Afterward the windlass allowed the outer plate of metal to settle firmly into place, and we proceeded along the passage and returned to the study.

Many trips did I make to the secret vault thereafter, but never could I understand in what manner the great door of shining steel was secured, as Dom Miguel always opened and closed it while we were in total darkness.

As the weeks rolled by I not only became deeply interested in my work, but conceived a still greater admiration for the one man whose powerful intelligence directed what I knew to be a gigantic conspiracy.

Spies were everywhere about Dom Miguel. One day we discovered his steward—an old and trusted retainer of the family—to be in the Emperor’s pay. But de Pintra merely shrugged his shoulders and said nothing. Such a person could do little to imperil the cause, for its important secrets could not be surprised. The grim vault guarded them well.

My duties occupying me only at night, my days were wholly my own, and they passed very pleasantly indeed, for my acquaintance with Lesba Paola had ripened into a close friendship between us—a friendship I was eager to resolve into a closer relation.

But Lesba, although frank and ingenuous in all our intercourse, had an effectual way of preventing the declarations of love which were ever on my tongue, and I found it extremely difficult to lead our conversation into channels that would give me an opportunity to open my heart to her.

She was an expert horsewoman, and we took many long rides together, during which she pointed out to me the estates of all the grandees in the neighborhood. Dom Miguel, whose love for the beautiful girl was very evident, seemed to encourage our companionship, and often spoke of her with great tenderness.

He would dwell with especial pride upon the aristocratic breeding of his ward, which, to do him justice, he valued more for its effect upon other noble families than for any especial advantage it lent to Lesba herself; for while Dom Miguel was thoroughly republican in every sense of the word, he realized the advantages to be gained by interesting the best families of Brazil in the fortunes of his beloved Cause, and one by one he was cleverly succeeding in winning them. My familiarity with the records taught me that the Revolution was being backed by the flower of Brazilian nobility—the most positive assurance in my eyes of the justice and timeliness of the great movement for liberty. The idea that monarchs derive their authority from divine sources—so prevalent amongst the higher classes—had dissolved before the leader’s powerful arguments and the object lessons Dom Pedro’s corrupt ministry constantly afforded. All thoughtful people had come to a realization that liberty was but a step from darkness into light, a bursting of the shackles that had oppressed them since the day that Portugal had declared the province of Brazil an Empire, and set a scion of her royal family to rule its people with autocratic sway.

And Lesba, sprung from the bluest blood in all the land, had great influence in awakening, in those families she visited, an earnest desire for a republic. Her passionate appeals were constantly inspiring her fellows with an enthusiastic devotion to the cause of liberty, and this talent was duly appreciated by Dom Miguel, whose admiration for the girl’s simple but direct methods of making converts was unbounded.

“Lesba is a rebel to her very finger-tips,” said he, “and her longing to see her country a republic is exceeded by that of no man among us. But we are chary of admitting women to our councils, so my little girl must be content to watch for the great day when the cause of freedom shall prevail.”

However, she constantly surprised me by her intimate knowledge of our progress. As we were riding one day she asked:

“Were you not impressed by your visit to the secret vault?”

“The secret vault!” I exclaimed. “Do you know of it?”

“I can explain every inch of its construction,” she returned, with a laugh; “everything, indeed, save the secret by means of which one may gain admission. Was it not Francisco’s idea? And is it not exceedingly clever?”

“It certainly is,” I admitted.

“It was built by foreign workmen, brought to Brazil secretly, and for that very purpose. Afterward the artisans were sent home again; and not one of them, I believe, could again find his way to my uncle’s house, for every precaution was taken to prevent their discovering its location.”

“That was well done,” said I.

“All that Francisco undertakes is well done,” she answered simply.

This faith in her perplexing brother was so perfect that I never ventured to oppose it. We could not have remained friends had I questioned either his truth or ability.

Madam Izabel I saw but seldom, as she avoided the society of the family and preferred the seclusion of her own apartments. On the rare occasions of our meeting she treated me with frigid courtesy, resenting any attempt upon my part to draw her into conversation.

For a time it grieved me that Dom Miguel’s daughter should regard me with so much obvious dislike and suspicion. Her sad story had impressed me greatly, and I could understand how her proud nature had resented the slanders of Francisco Paola, and writhed under them. But one evening an incident occurred that served to content me with Madame Izabel’s aversion, and led me to suspect that the Minister of Police had not been so guilty as I had deemed him.

It was late, and Dom Miguel had preceded me to the domed chamber while I carried the records and papers to be deposited within the vault.

After raising the first trap my employer, as usual, extinguished the candle. I heard the customary low, grating noise, but before the shooting of the bolts reached my ears there was a sharp report, followed by a vivid flash, and turning instantly I beheld Madam Isabel standing beside us, holding in her hand a lighted match and peering eagerly at the surface of the trap.

My eyes followed hers, and while Dom Miguel stood as if petrified with amazement I saw the glitter of a gold ring protruding from one of the many curious indentations upon the plate. The next instant the match was dashed from her grasp and she gave a low cry of pain.

“Light the candle!” commanded de Pintra’s voice, fiercely.

I obeyed. He was holding the woman fast by her wrist. The ring had disappeared, and the mystery of the trap seemed as inscrutable as ever.

Dom Miguel, greatly excited and muttering imprecations all the way, dragged his daughter through the passage and up the stairs. I followed them silently to the chief’s study. Then, casting the woman from him, de Pintra confronted her with blazing eyes, and demanded:

“How dare you spy upon me?”

Madam Izabel had become cool as her father grew excited. She actually smiled—a hard, bitter smile—as she defiantly looked into his face and answered:

“Spy! You forget, sir, that I am your daughter. I came to your room to seek you. You were not here; but the door to this stairway was displaced, and a cold air came through it. Fearing that some danger menaced you I passed down the stairs until, hearing a noise, I paused to strike a match. You can best explain the contretemps.”

Long and silently Dom Miguel gazed upon his daughter. Then he said, abruptly, “Leave the room!”

She bowed coldly, with a mocking expression in her dark eyes, and withdrew.

As she passed me I noted upon her cheeks an unwonted flush that rendered her strikingly beautiful.

Deep in thought de Pintra paced the floor with nervous strides. Finally he turned toward me.

“What did you see?” he asked, sharply.

“A ring,” I answered. “It lay upon the trap, and the stone was fitted into one of the numerous indentations.”

He passed his hand over his brow with a gesture of despair.

“Then she saw it also,” he murmured, “and my secret is a secret no longer.”

I remained silent, looking upon him curiously, but in deep sympathy.

Suddenly he held out his hand. Upon the little finger was an emerald ring, the stone appearing to be of no exceptional value. Indeed, the trinket was calculated to attract so little attention that I had barely noticed it before, although I remembered that my employer always wore it.

“This,” said he, abruptly, “is the key to the vault.”

I nodded. The truth had flashed upon me the moment Madam Izabel had struck the match. And now, looking at it closely, I saw that the stone was oddly cut, although the fact was not likely to impress one who was ignorant of the purpose for which it was made.

The chief resumed his pacing, but presently paused to say:

“If anything happens to me, my friend, be sure to secure this ring above all else. Get it to Paola, or to Fonseca, or Piexoto as soon as possible—you know where they may be found. Should it fall into the hands of the royalists the result would be fatal.”

“But would either of your associates be able to use the ring, even if it passed into their possession?” I asked.

“There are two hundred indentations in the door of the trap,” answered de Pintra, “and the stone of the ring is so cut that it fits but one of these. Still, if our friends have time to test each cavity, they are sure to find the right one, and then the stone of my ring acts as a key. My real safety, as you will observe, lay in the hope that no one would discover that my ring unlocked the vault. Now that Izabel has learned the truth I must guard the ring as I would my life—more, the lives of all our patriotic band.”

“Since you suspect her loyalty, why do you not send your daughter away?” I suggested.

“I prefer to keep her under my own eye. And, strange as her actions of to-night seem, I still hesitate to believe that my own child would conspire to ruin me.”

“The secret is not your own, sir,” I ventured to say.

“True,” he acknowledged, flushing deeply, “the secret is not my own. It belongs to the Cause. And its discovery would jeopardize the revolution itself. For this reason I shall keep Izabel with me, where, admitting she has the inclination to betray us, she will not have the power.”

After this night he did not extinguish the light when we entered the vault, evidently having decided to trust me fully; but he took pains to secure the trap in the study floor so that no one could follow us. After watching him apply the key several times I became confident that I could find the right indentation without trouble should the occasion ever arise for me to unlock the vault unaided.

Days passed by, and Madam Izabel remained as quiet and reserved as if she had indeed abandoned any further curiosity concerning the secret vault. As for my fellow-rebel, the Senhorita Lesba, I rode and chatted with her in the firm conviction that here, at least, was one secret connected with the revolution of which she was ignorant.