There seemed to be no end to the stairway. It wound and twisted about in a bewildering fashion, and, before they reached the top, Frank and Archie came to the conclusion that they had either been a long way under the ground, or else that the rancho was a much taller building than they had imagined it to be. At last, however, their guide pushed open a door, and the boys found themselves in the same room to which he had conducted them when they first arrived at the rancho. Still closely followed by his watchful companions, the Don went straight across the room, and stopped in front of a wardrobe.

“Now, leetle poys,” said he, addressing himself to Archie, “you got the keys. Make dis door open.”

Archie quickly found a key that would fit the lock, and when the boys entered the wardrobe, they discovered that, although it was used as a receptacle for clothing, it was intended to conceal a door that led into some secret apartment. When this door had been opened—it was so heavy that it taxed Archie’s strength to the utmost to move it—the cousins found themselves in a room, about twenty feet square, which had one peculiarity that they noticed as soon as they crossed the threshold. There was not a single opening in it; and when Archie had shut the door, they found themselves surrounded on all sides by rough stone walls. Even the door itself, which closed behind them with the sharp click of a spring lock, could not be seen.

“I say, Don,” exclaimed Frank, “what use do you make of this dungeon? I don’t see any thing stowed away here.”

The chief’s answer was not given in words. He was standing close by Frank’s side, and before the latter could move, he had suddenly jerked the lantern from his hand, and dashed it upon the floor, smashing it into a thousand pieces, and extinguishing the light. As quick as thought Frank bounded forward, and made a blind clutch at the place where he had last seen the Don, but with no other result than to come in violent contact with the wall. A moment afterward, the astonished and bewildered boys heard a grating sound at the other side of the room, and the Don’s voice calling to them through the darkness.

“Dis ish all right,” said he. “Dere’s somethings shtowed away here now, ain’t it? It’s petter you shtays here awhile.”

The truth flashed through the boys’ minds at once—they were prisoners again. In spite of all their vigilance, the chief had succeeded in carrying out the plan he had formed while he was watching the operation of binding Pierre Costello. His movements had been so rapid, that, even had his captives been aware of his intention, they could not have prevented him from carrying it into execution. Before they could tell what was the matter, the lantern had been smashed, their treacherous enemy had made his exit from the room in some mysterious manner, and they were alone in the darkness.

“We’re in for it now,” panted Archie, sinking down upon the floor all in a heap. “We’ve got out of some tight places to-night, but there is no escape from this predicament. The Don will soon be back with his men.”

“And if they once get their hands upon us, we need never expect to see home again,” said Frank. “Give me some of your matches, and we will examine the walls of this dungeon. There’s a spring to that door, and if we can find it, we can get out.”

After the matches had been lighted, the boys found that the first difficulty to be overcome was the finding of the door. They did not know where to look for it, for the walls appeared to be as solid as the ground. They made the circuit of the room several times, lighting new matches as fast as the old ones were consumed, and carefully examining each separate stone in the wall, from the floor up to a level with their heads; but nothing in the shape of a spring or lock rewarded their search. Then they turned their attention to the floor; but, if there was any opening in the solid oak planks, it could not be found. Five minutes—it seemed much longer to the frightened and excited boys—were passed in this way, and then, for the first time that night, Frank’s courage and fortitude were utterly exhausted.

“It’s no use,” said he. “The Don got out somewhere, but it is very evident that we can’t. We might as well sit down, and wait for him to come in and dispose of us. Do you see any thing encouraging?” he added, noticing that his cousin was holding a match above his head, and closely examining the roof of the dungeon.

“I believe I do,” replied Archie. “Isn’t that a scuttle?”

“That’s just what it is,” exclaimed Frank, joyfully; “and it is fastened with hooks.”

“Oh, if we could only get up there,” cried Archie. “But there isn’t a thing here for a fellow to stand upon.”

“I’ve got a pair of shoulders. Come here, and I will hold you up.”

After burning another match to determine the exact position of the scuttle, Frank took his stand directly beneath it, and in a moment more, Archie was balanced on his shoulders, and panting loudly, as he strove with nervous haste to unfasten the hooks. Every thing bothers when one is in a hurry, and one’s fingers are all thumbs. It was awkward working in that intense darkness, and, besides, the hooks had been driven into the staples so tightly, that it required the outlay of all Archie’s strength to start them. But patience and perseverance conquered at last, and in an excited voice he informed his cousin that he had unfastened the scuttle, and asked him if he should open it.

“Of course,” replied Frank.

“But how do we know what we shall find on the other side? Perhaps it leads into a room full of Mexicans.”

“We must run that risk. Venture nothing, gain nothing, you know.”

Frank awaited the issue of events with a good deal of anxiety. He heard the heavy scuttle lifted slowly and cautiously from its place, then a smothered cry of exultation, and the weight was suddenly lifted from his shoulders. Upon looking up, he saw the stars shining down upon him through the scuttle-hole, and his cousin’s heels disappearing over the combings.

“We are safe now,” whispered Archie, thrusting his head into the opening, and extending his hand down into the darkness. “I am on the roof of the rancho. Give us your fist.”

“I can’t reach you,” replied Frank.

Archie hesitated a moment, and then pulled off his jacket, and firmly grasping one of the sleeves, threw the other down to his cousin. One hundred and fifty pounds was no light weight for a boy of his size to sustain, but he clung manfully to the jacket, while Frank went up, hand-over-hand, as a sailor goes up a rope. He soon ascended high enough to seize the combings of the scuttle, and in a moment more stood safe upon the roof.

The cousins did not stop to congratulate themselves upon their good fortune. Time was much too precious for that, and, besides, they did not yet regard their escape as a settled thing. There was the creek to be crossed; a belt of timber to be passed; and five miles of lonely prairie to be traversed, before they reached their uncle’s rancho; and there was no knowing what might happen to them while they were making this journey. Their first care was to put the scuttle back in its place, so that the Don, when he returned to the dungeon, should not immediately discover the manner of their escape, and the next to reconnoiter the ground before them. They found themselves on the roof of a wing of the rancho—a space about twenty feet square. On three sides was a stone parapet, two feet high, and on the fourth loomed up the walls of the main building. In this wall was a door, which opened upon the wing. The boys merely glanced at it, and scarcely thought of it again; but they afterward had good cause to remember it. They looked all around them, but there was no one in sight; they listened intently, but could hear nothing.

“The coast seems to be clear,” said Archie, walking to the parapet and looking cautiously over, “and we had better be off. It isn’t more than fifteen or twenty feet to the ground, and we can hang by our hands and drop without much danger of injuring ourselves.”

“Be careful,” said Frank. “A sprained ankle wouldn’t be a funny thing, just now.”

The boys jumped upon the wall, and were on the point of swinging themselves over, when an interruption they had not dreamed of arrested their movements. Frank’s quick ear caught the faint tramping of horses’ hoofs. He laid his hand upon his cousin’s arm, and they sprang back to the roof, and concealed themselves behind the parapet.

“Something is always bothering us,” said Archie, straining his eyes through the darkness in the direction from which the sound came. “What’s up now, I wonder!”

If Frank had known just what was about to transpire, he could not have described it in less time than the scene occupied in taking place. While Archie was speaking, the sound of the horses’ hoofs ceased, and a faint light, like that emitted by a match, blazed up in the bushes on the opposite side of the creek. The signal (for the boys were sure it was a signal) was repeated twice, and then arose a commotion in the house, as if men were running hurriedly about. This continued for a few seconds, and then a flatboat suddenly made its appearance in the creek. Where it came from, the boys could not imagine; but there it was, and there was a man in it, who was sculling it toward the opposite bank.

“By—gracious!” whispered Archie, in great excitement. “We are going to witness the very scene that frightened old Bob so badly.”

“But Bob must have been dreaming,” answered Frank. “He said the boat was ferried across without hands, and that man is using an oar.”

Our heroes were too deeply interested in what was going on to continue the conversation. Archie pulled off his sombrero, and pushed back his sleeves, as if he were preparing for a trial of strength with somebody, while Frank settled himself into a comfortable position behind the parapet, after the manner of a boy who had selected his favorite book from the library, and seated himself in an easy chair to enjoy it. They kept a sharp lookout, for they were determined that not even the smallest incident should escape their notice. They had an opportunity now to learn the secret of these strange doings, and, when they were over, they would know as much about them as Don Carlos himself.

At the same moment that the flatboat appeared, the boys heard the grating noise below them, and suddenly the banks of the creek and the woods, for two hundred yards around, which had been shrouded in darkness an instant before, were flooded with light.

“I know what Bob’s ‘streaks of fire’ are now,” said Frank.

“That light comes from a dark-lantern,” chimed in Archie. “There’s only one thing, so far, that I can’t understand, and that is, where that boat came from in such a hurry. What’s that?”

Just then a large white object, which appeared to unfold itself as it moved along, came into view, and rolled down the bank toward the creek. It stopped when it reached the water’s edge, thus forming a walk, which extended from the creek to the walls of the rancho. This was another thing that Archie could not understand, and neither could Frank. They knew that it was what the trapper had called the “bridge of clouds,”—and there it was, “rolling and tumbling, like the smoke from the mouth of a cannon,” just as Dick had described it to them—but what was it made of? that was the question. Of course it couldn’t be a cloud, but it certainly looked like one. Archie sank lower behind the parapet, and muttered his favorite expression a good many times, and Frank puffed out his cheeks, and scratched his head to stir up his ideas.

While the bridge of clouds (the boys did not know what else to call it) was placing itself in position on that side of the creek, a similar operation had been going on on the opposite bank. The boat had by this time crossed the creek, and a white object, like the one just described—another bridge of clouds—extended from it into the woods. Presently, two horsemen appeared, riding down the bridge toward the boat. One was mounted on Roderick, and the other on King James; and each led a horse which had doubtless been stolen that night. They rode upon the flatboat, the bridge along which they had just passed rolled itself up after them, and the boat began to move across the creek. It was plain, now, that the old trapper had not been dreaming. The horsemen were still in their saddles; the Mexican, who had gone over in the boat, was standing quietly in the stern; the oar lay upon the bottom where he had thrown it; and yet the boat moved rapidly through the water. There was no mistake about it, for the boys could see the whole proceeding as plainly as though it had been broad daylight. The boat was certainly coming across the creek, and it was equally certain that not one of its three passengers was propelling it. A dozen oarsmen could not have sent it through the water as rapidly as it was moved by that invisible power. It was not more than half-a-minute in crossing the creek, and as soon as it touched the bank, the horsemen rode out on the bridge of clouds, and came toward the rancho. Frank and Archie kept close watch of their movements, thrusting their heads as far over the parapet as they dared, and it seemed to them that the horsemen went into the wall. They suddenly disappeared somewhere very suddenly; and no sooner were they out of sight, than the bridge of clouds rolled itself up behind them, the light was extinguished, and darkness once more settled down over the rancho.

These various incidents followed one another with a rapidity that was utterly bewildering. The horsemen had crossed the creek, and were safe in the rancho, almost before the boys knew it. They had moved as swiftly and silently as spirits; and when they had passed out of sight, Archie struck the parapet with his fist, to make sure that he was awake. He felt the cold chills creeping along his back, and he did not wonder now that old Bob had been frightened. He was willing to confess that he was frightened himself.

“Well!” said Frank, after a moment’s pause.

“Don’t ask me any questions,” replied Archie. “I don’t know any more about it now than I did before. Where did those fellows go?”

“What was that white thing the horses walked on, and what moved it? I didn’t see any one near it!”

“Where did that flatboat come from, and where could it have gone so suddenly? It disappeared the instant the horsemen left it.”

“No doubt we shall know all about it some day,” said Frank—“that is, if we succeed in making our escape. I wonder if the coast is clear now?”

“No, it isn’t,” answered Archie. “See there!”

Frank looked over the parapet, and saw a Mexican standing in the shadow of the wall beneath them. He had doubtless been stationed there to see if the horsemen were pursued. The boys wished him a thousand miles away, for he was sadly interfering with their arrangements. They waited impatiently for him to follow the robbers into the rancho, but he seemed to have no such intention. He stood there as upright as a post, and as silent and motionless.

“Are we not having miserable luck?” asked Archie, impatiently. “Let’s jump down on him, before he knows it. We can both manage him.”

“But we would alarm the rest of the band,” replied Frank. “Let’s drop down on the other side, and go around the rancho.”

The attention of the boys had been so fully occupied with what had just transpired, that they had not thought of looking for enemies in their rear. While they were watching the Mexican beneath them, the door in the wall of the main building, of which we have before spoken, was noiselessly opened, and several Rancheros, headed by Don Carlos, came out and approached the boys on tip-toe. As the latter arose to their feet to carry out the plan Frank had suggested, Archie’s collar was seized in a strong grasp, and his cousin looked up just in time to see a long, bony hand stretching out toward him. It was the robber chief’s hand; but it was much too slow in its movements to make a prisoner of Frank Nelson. The boy lingered just long enough to see that the Don was backed up by a force too strong to be successfully resisted, and then, striking up the threatening hand, he jumped to the parapet and swung himself over. He did not immediately let go his hold, but looked down to take a survey of the ground beneath him. He wanted to strike squarely on his feet, in order to be on equal terms with the sentinel who would doubtless pounce upon him at once. He hung suspended in the air but a moment, but that was long enough for the Don to reach the parapet, and bend over and seize him by the collar.

“Hold on, leetle poys,” exclaimed the chief. “It’s petter you comes back here. Ach! Dis ish von grand shwindle,” he yelled, changing his tone very suddenly. “Vat you making here, leetle poys?”

The Don was greatly alarmed now, for he was being dragged over the parapet. When he seized Frank, he did not attempt to pull him back upon the roof, but braced himself, intending to hold fast to his prisoner until some of his men could come to his assistance. Frank understood his plans; and knowing that the loss of a single instant might be fatal to him, he quickly loosened his grasp upon the wall, and seized the Don by the hair. He hoped by this move to compel his enemy to let go his hold; but it had a very different result. The chief, not being equal to the task of sustaining a dead weight of one hundred and fifty pounds by the hair of his head, suddenly lost his balance, and he and Frank fell whirling through the air.