“Yes, sir; I expected it,” cried John Manning, as the mules all stopped short, their leader having suddenly swerved aside to avoid a little avalanche of stones and masses of rocks which came tearing down from far on high, right across their course.

It began by the dislodging of one great mass, which was forced over from a rocky shelf, and before this had rolled half-way, it had started hundreds more, the attempt being so well contrived that the pieces of rock, which came leaping and bounding down with a clashing sound like thunder, would certainly have crushed one or more of the mules, but for their quick appreciation of the danger.

Two sharp replies to this attack were given from the loaded pieces, and the Indians disappeared; but when, after a great deal of coaxing, the mules were got into motion once more, the colonel urging the leader round beyond where the stones had fallen, the boys uttered a warning cry, for another mass of rock was started from high up on the other side, and with such good effect that the rush of stones it started caught the tiny caravan half-way, and to the misery and despair of all, one of the best mules lay with its pack half buried, and the poor creature’s head crushed almost flat.

This time the boys fired up at a single man perched fully twelve hundred feet above the narrow bottom of the gorge, and he dropped out of sight, while the colonel and John Manning leaped down again, and rapidly removed the stones which impeded them in their efforts to loosen the pack-ropes and remove the load to another mule.

This was a hindrance of a good half-hour, and the colonel looked very stern as he gave the order to advance again, when they gained about a mile, the gorge opening a little. Then the huge towering walls contracted once more, and a black-looking prospect opened before them, for there, so narrow that there was barely room for the mules to go singly, was their way, through a black-looking rift, above which the mountains on either side rose in shelves admirably adapted for the enemy’s defence, and promising so ill for the little party, that the colonel hesitated for a minute while he used his glass. Then, as all was still, no sign of an enemy visible, he gave the order to advance, in the hope that the place was too precipitous for the Indians to occupy.

Vain hope! Ten minutes later the mule he rode lay quivering on the ground; the colonel having the narrowest of narrow escapes from a terrible death.

“Forward!” he said firmly, but as he spoke, another avalanche and another came thundering down, and seeing the madness of attempting to proceed, he gave the word to retreat.

It was needless, for the mules had already sprung round, and were hurrying back at a rate that was faster than anything they had yet shown.

There was no yell of triumph from on high, and no sign of enemy on either hand as they rode back, face to face with the fact that exit from the gorge in that direction was impossible, and that unless they could find some side ravine leading in the direction they wished to pursue, there was nothing for it but to retrace their steps right to the cinchona cutters’ camp, and from thence make their way home by the road they came.