"They passed here less than ten minutes ago, Señor," he said as he remounted and splashed across the brook. "I can tell this by the water which dripped from their horses, and the degree of moisture still remaining." On they went to the accompaniment of the thud of the well-shod hoofs, the creak of leather, the jangle of bit and spur. Tomas was still watching the road, when without apparent reason he stopped. "What is the trouble?" asked Dick, reining in the black charger on arriving abreast of his companion, but before answering the native looked about him cautiously. "I have lost their trail, Señor. They have left the road." "Which way did they turn, Tomas?" "I cannot tell without going back, but I believe to the right." "Is there any cross trail or road?" "No, and there is no reason that I know for them to leave the road." "Why do you suppose they have done so?" "Quien sabe?"[#] answered Tomas, giving his shoulders a shrug which carried as much meaning as his words. "Possibly they are in hiding and watching us to ascertain if they are being followed. If so, it would not be wise to retrace our steps in case it is your desire to learn what became of them. But now that we are evidently beyond them, I think we are fortunate, and would suggest we proceed at once on our way. So far we have been unusually lucky, having met with no rebels." [#] Quien sabe--Who knows? That there was wisdom in the Indian’s words could not be denied, but Dick felt a distinct sense of disappointment as he looked about him in the vain hope of seeing something of those they had been following so closely. About a half mile to the west an almost bare hill stuck its summit high into the glaring blue sky. Its slopes were cone shaped and fringed with a short stubby growth. In spite of disappointment, it was impossible to see the beautiful symmetry of the hill without admiring it, and as Dick watched, a cloud of smoke burst forth from its apex. Knowing the volcanic nature of the country he was nevertheless surprised at the sight, as Mount Momotombo, rising from the waters of Lake Managua, was the only active volcano in this immediate neighborhood. "Is that small hill an active volcano, Tomas?" he asked. The native looked long and searchingly at the smoking hilltop. At first his face expressed fear and amazement, followed in turn by a look of question, and then of understanding. "No, no, Señor, it is not a volcano. It is a signal. Someone is sending smoke signals." "Smoke signals? What do they mean?" "They may mean anything. It is a method used by my people long ago and often resorted to by the natives of Nicaragua. If you notice the smoke is interrupted; sometimes long columns, sometimes short clouds or puffs." "Are you able to read the message?" "No! one has to know the code, Señor."