Horses!” exclaimed Natividad. “Then we have them. They are probably making for the Cuzco, or some place round Titicaca, But they are bound to pass through Veintemilla’s lines, and we shall catch them at Canete or Pisco.”

As Natividad had surmised, the riders were cavalrymen sent out from Chorillos at his order. They ran toward them, Uncle Francis questioning the Marquis, who did not answer. Indeed, Don Christobal, doubly anxious now that his son had left his side, could not contain himself. Hardly had the troopers dismounted than he swung himself into the nearest saddle, and rode off after Dick.

“Sheer madness,” growled Natividad. “If they ever overhaul the Indians, they are lost.”

“What are we going to do now?” demanded Uncle Francis. Maria-Teresa’s fate moved him deeply, particularly from a literary point of view, but under the circumstances he asked no better than to keep a little in the background.

“We can only follow at a distance,” replied Natividad.

“Excellent... excellent... find out where they are making for, and all that sort of thing.”

“There are still laws, a police force and troops in Peru, se?or. We are not afraid of the Indians.”

With which he turned to the four soldiers who had joined them, and who represented what remained of the military force op the costa. Uncle Francis, already delighted with Natividad’s plan of following at a distance, approved of it even more warmly when he found that this little escort was to accompany them.

Three policemen mounted on mules, coming from the direction of Callao, now appeared on the road. Natividad at once requisitioned the mules for his expedition. Before starting, however, he went back into the casa to write a hurried letter to President Veintemilla, explaining what had happened. He did so with a certain malice, remembering that ten years ago this same president had been Chief of Police, and had threatened to suspend him for his “mad reports.”

One of the policemen, entrusted with the letter, started back toward Callao at once. The two others were ordered to take charge at the hacienda and begin a preliminary enquiry. Then Natividad and Uncle Francis mounted two of the commandeered mules, the third being taken by the soldier whose horse had been carried off by Don Christobal. When the soldiers saw that they were heading for the sierra instead of Chorillos, there was a grumble, but Natividad silenced them. “Forward,” he ordered, and they, in their turn, entered the ravine.

“We can, at all events, travel as fast as the mammaconas,” said the Chief of Police to Uncle Francis.

“The mammaconas? Were they here then?” The scientist, intensely interested, urged his mount alongside Natividad’s.

“Yes se?or... the mammaconas... and three head priests of the temple... only they may touch the Virgin of the Sun.... se?or, for the past fifteen years I have known all this, but they called me a lunatic. Why should we suppose that the Indians have changed? Do they not eat, drink, and get married just as they did five centuries ago? If their outward customs have not changed, why should their secret rites have done so? Why, se?or, why?... But nobody will believe me. It all began when I was a young man. I had to investigate a mysterious crime, the only possible explanation for which was a religious one. You must not forget that you are dealing with Incas to this day.... And I got my knuckles rapped.... Five years later, when the Orellana girl disappeared, they treated me in the same way. So I let them give what explanation they liked, and worked on my own. I speak Quichua like a native now, se?or. I also learned Aimara, which is their sacred language in the Cuzco and round Titicaca.... That’s where they are making for now; some hidden temple, where their priests have been working since the days of the conquest.”

Uncle Francis looked at his companion suspiciously. Were they all engaged in a huge practical joke at his expense? This Chief of Police was singularly calm under the circumstances; off-handed, almost gay.

“We are sure to catch them, are we not?”

“Of a surety, se?or. Dios mio, be content! We will catch them.... How can they possibly escape? We are on their heels; if they stick to the mountains, they run into our troops; if they go down into the costa, every corregidor (mayor) is at my orders.”

There was a moment’s silence, and he went on:—

“Will you not put on that cloak at your saddle-bow, se?or? The nights are chilly, and we are nearing the cordilleras.... The only road, you see. They must have passed here. At dawn, we shall be able to see their trail distinctly.... If only those crazy people who dashed on ahead do not make fools of themselves.... A plucky youngster, little Christobal.... We shall soon overhaul them.... One does not climb these mountains as a bull jumps over the barrier at the ring....”

Natividad’s garrulous flow of words was interrupted by a chuckle from Uncle Francis. Not a little astonished, he asked him what he meant, but Mr. Montgomery contented himself with replying:—“I understand, I understand.” Natividad, who did not understand, eyed him doubtfully.

Just before day-break they reached the first masses of the true Andes. Their mounts did not appear over-tired, and after a two-hours’ halt at a wayside guebrada, where beasts and men obtained food, they continued the journey. Over them towered the giant mountain chain, blazing in the molten light of dawn.

The half-breeds at the guebrada could not, or would not, give them any informat............