"How very strange!" remarks Ludwig.

"Not at all strange, _senorito_; but just as it should be, and as we might have expected."

"But what has caused it?"

"Oh, cousin," answered Cypriano, who now comprehends all. "Can't you see? I do."

"See what?"

"Why, that the dust has settled down over the plain; and the rain coming after, has converted it into mud."

"Quite right, Senor Cypriano," interposes Gaspar; "but that isn't the worst of it."

Both turn their eyes upon him, wondering what worse he can allude to.

Cypriano interrogates:--

"Is it some new danger, Gaspar?"

"Not exactly a danger, but almost as bad; a likelihood of our being again delayed."

"But how?"

"We'll no longer have track or trace to guide us, if this abominable sludge extend to the river; as I daresay it does. There we'll find the trail blind as an owl at noontide. As you see, the thing's nearly an inch thick all over the ground. 'Twould smother up the wheel-ruts of a loaded _carreta_."

His words, clearly understood by both his young companions, cause them renewed uneasiness. For they can reason, that if the trail be obliterated, their chances of being able to follow the route taken by the abductors will be reduced to simple guessing; and what hope would there be searching that way over the limitless wilderness of the Chaco?

"Well?" says Gaspar, after they had remained for some moments gazing over the cheerless expanse which extends to the very verge of their vision, "it won't serve any good purpose, our loitering here. We may as well push on to the river, and there learn the worst--if worst it's to be. _Vamonos_!"

With this, the Spanish synonym for "Come along!" the gaucho gives his horse a dig in the ribs, with spur rowels of six inches diameter, and starts off at a swinging pace, the others after.

And now side by side go all three, splashing and spattering through the mortar-like mud, which, flung up in flakes by their horses' hoofs, is scattered afar in every direction.

Half an hour of quick cantering brings them back upon the Pilcomayo's bank; not where they had parted from it, but higher up, near the mouth of the _arroyo_. For Gaspar did not deem it necessary to return to that prophetic tree, whose forecast has proved so unfailing. To have gone back thither would have been a roundabout of several miles, since they had made a cross-cut to reach the cavern; and as on the way they had seen nothing of the Indian trail, it must needs have continued up the river.

But now, having reached this, they cannot tell; for here, as on all the plain over which they have pa.s.sed, is spread the same coating of half-dried dirt, fast becoming drier and firmer as the ascending tropical sun, with strengthened intensity, pours his hot beams upon it.

It has smothered up the Indian's trail as completely as it snow several inches deep lay upon it. No track there, no sign to show, that either horses or men ever pa.s.sed up the Pilcomayo's bank.

"_Caspita_!" exclaims the gaucho, in spiteful tone. "It is as I antic.i.p.ated; blind as an old mule with a _tapojo_ over its eyes. May the fiends take that _tormenta_!"

CHAPTER THIRTY TWO.

STOPPED BY A "RIACHO."

For a time the trackers remain at halt, but without forsaking their saddles, pondering upon what course they should pursue, or rather, what direction they ought to take.

Only a short while are they undecided. It seems good as certain that the Indians have kept to the river, for some distance further on, at all events. Therefore, it will be time enough to enter upon a more prolonged deliberation, when they come to a point where this certainty ceases. Thus reflecting, they start off afresh, with their horses'

heads as before.

Going at good speed as ever, in a few minutes they arrive at the confluence of the _arroyo_ with the greater river; the former here running between banks less "bluffy" than above, where it pa.s.ses the cavern. Still they are of sufficient elevation to make a sharp descent towards the channel of the stream, and a corresponding ascent on its opposite side. But instead of an impediment, the trackers find this an advantage; giving them evidence that the Indians have gone across the _arroyo_. For their horses' tracks are distinctly traceable on the steep faces of both banks; the dust either not having settled there, or been washed off by the rain which fell after.

Without difficulty they themselves ride across; for the rapid-running stream has returned to its ordinary dimensions, and is now quite shallow, with a firm gravelly bed. Once on its western side, however, and up to the level of the _campo_ beyond, they are again at fault; in fact, have reached the point spoken of where all certainty is at an end.

Far as they can see before them, the surface is smeared with mud, just as behind, and no sign of a trail visible anywhere. Like enough the Indians have still continued on along the river, but that is by no means sure. They may have turned up the _arroyo_, or struck off across the pampa, on some route known to them, and perhaps leading more direct to whatever may be their destination.

It is all conjecture now; and upon this they must rely. But the weight of probability is in favour of the pursued party having kept to the river, and Gaspar is of this opinion. After riding some distance up the western bank of the _arroyo_, and seeing no trail or track there, he again returns to where they had crossed, saying:--

"I think we may safely stick to the river. I'm acquainted with its course for at least thirty leagues further up. At about half that distance from here it makes a big elbow, and just there, I remember, an old Indian path strikes off from it, to cross a _traveria_. Ha! that's good as sure to be the route these redskins have taken. For now, I think of it, the path was a big, broad road, and must have been much-travelled by Indians of some kind or other. So, _muchachos_; we can't do better than keep on to where it parts from the water's edge.

Possibly on the _traveria_, which chances to be a _salitral_ as well, we may find the ground clear of this detestable stuff, and once more hit off the _rastro_ of these murderous robbers."

His young companions, altogether guided by his counsels, of course offer no objection; and off they again go up the bank of the broad deep river.

Nor less swiftly do they speed, but fast as ever. For they are not impeded by the necessity of constantly keeping their eyes upon the earth, to see if there be hoof-marks on it. There are none; or if any, they are not distinguishable through the thick stratum of slime spread over all the surface. But although going at a gallop, they do not get over much ground; being every now and then compelled to pull up--meeting obstructions they had not reckoned upon. These in the shape of numerous little streamlets, flowing into the river, most of them still in freshet from the late rain. One after another they ford them, none being so deep as to call for swimming. But they at length come upon one of greater depth and breadth than any yet pa.s.sed, and with banks of such a character as to bring them to a dead stop, with the necessity of considering whether it can be crossed at all. For it is a watercourse of the special kind called _riachos_, resembling the _bayous_ of Louisiana, whose sluggish currents run in either direction, according to the season of the year, whether it be flood-time or during the intervals of drought.

At a glance, Gaspar perceives that the one now barring their onward progress is too deep to be waded; and if it be possible to pa.s.s over it, this must be by swimming. Little would they regard that, nor any more would their animals; since the pampas horse can swim like an otter, or _capivara_. But, unfortunately, this particular _riacho_ is of a kind which forbids even their swimming it; as almost at the same glance, the gaucho observes, with a grunt expressing his discontent. On the stream's further sh.o.r.e, the bank, instead of being on a level with the water surface, or gently shelving away from it, rises abruptly to a height of nigh six feet, with no break, far as can be seen, either upward or downward. Any attempt to swim a horse to the other side, would result in his being penned up, as within the lock-gates of a ca.n.a.l!

It is plainly impossible for them to cross over there; and, without waiting to reflect further, the gaucho so p.r.o.nounces it; saying to the others, who have remained silently watching him:--

"Well, we've got over a good many streams in our morning's ride, but this one beats us. We can't set foot on the other side--not here, at all events."

"Why?" demands Cypriano.

"Because, as you can see, _senorito_, that water's too deep for wading."

"But what of that? We can swim it, can't we?"

"True, we could; all that and more, so far as the swimming goes. But once in there, how are we to get out again? Look at yonder bank.

Straight up as a wall, and so smooth a cat couldn't climb it, much less our horses; and no more ourselves. If 'twere a matter of wading we might; but, as I can see, all along yonder edge it's just as deep as in mid-stream; and failing to get out, we'd have to keep on plunging about, possibly in the end to go under. _Carramba_! we mustn't attempt to make a crossing here."

"Where then?" demands Cypriano, in torture at this fresh delay, which may last he knows not how long.

"Well," rejoins the gaucho, reflectingly, "I think I know of a place where we may manage it. There's a ford which can't be very far from this; but whether it's above or below, for the life of me I can't tell, everything's so changed by that detestable _tormenta_, and the ugly coat of plaster it has laid over the plain! Let me see," he adds, alternately turning his eyes up stream and down, "I fancy it must be above; and now I recollect there was a tall tree, a _quebracha_, not far from the ford. Ha!" he exclaims, suddenly catching sight of it, "there's the bit of timber itself! I can tell it by that broken branch on the left side. You see that, don't you, _hijos mios_?"

They do see the top of a solitary tree with one branch broken off, rising above the plain at about two miles' distance; and they can tell it to be the well-known species called _quebracha_--an abbreviation of _quebrahacha_, or "axe-breaker," so named from the hardness of its wood.

"Whether it be by wading or swimming," Gaspar remarks in continuance, "we'll get over the _riacho_ up yonder, not far from that tree. So, let's on to it, _senoritos_!"

Without another word, they all wheel their horses about, and move off in the direction of the _quebracha_.

CHAPTER THIRTY THREE.

A FISH DINNER AT SECOND-HAND.

As they make towards the tree, which has erst served others than themselves as a guide to the crossing-place, the nature of the ground hinders their going at great speed. Being soft and somewhat boggy, they are compelled to creep slowly and cautiously over it.

But at length they get upon a sort of ridge slightly elevated above the general level, though still unsafe for fast travelling. Along this, however, they can ride abreast, and without fear of breaking through.