They had also brought away with them their packs of food, but they did not mind the additional weight of the weapons, which were worth more to them than gold or jewels.  They listened a minute or two to see if any alarm had been raised, but no sound came from the Hall of Pillars, and with light steps and strong hearts they began another march on their northward journey.

They traveled by the moon and stars, and, as they were not hindered now by any great tangle of undergrowth, they made many miles before dawn, although they were ascending steadily.  They had come upon the edge of the great central plateau of Mexico, which runs far into the north and which includes much of Texas.  Before them lay another and great change in the country.  They were now to enter a land of little rain, where they would find the ragged yucca tree, the agave and the cactus, the scrubby mesquite bush and clumps of coarse grass.  But they had passed through so much that they did not fear it.

They hunted for an hour after sunrise, before they found a small brook, at which they drank, and, in spirit, returned the thanks which Obed had said so emphatically were due.  Then, wrapped in the useful serapes, they went to sleep once more in a thicket.  They had been sure that the Mexicans could not trail them, and their confidence was justified.  When they awoke in the afternoon no human being was in sight, and their loaded rifles lay undisturbed beside them.

Then they entered upon the plain, plodding steadily on over a dusty gray landscape, but feeling that their rifles would be ample protection against anything that they might meet.  The sun became very hot, and they longed at times for the shade of the forest that they had left behind, but they did not cease their march.  Off to their left they saw towering mountains with a green film along their slopes that they knew to be forests of oak and pine; and such was the nature of man that they looked at them regretfully.  Obed White, glancing at Ned, caught Ned glancing at him, and both laughed.

“That’s it,” said Obed.  “How precious is the thing that slips away.  When we were in the forest we wanted the open country, but now in the open country we want the forest.  But we’re making progress, Ned.  Don’t forget that.”

“I don’t,” said Ned.  “But when we get further North into the vast stretches of the arid plateau, we must have something more to carry—­water bottles.”

“That’s so.  We can’t do without them.  Maybe, too, Ned, we can pick up a couple of good horses.  They’d be a wonderful help.”

“We’ll hope for everything we need,” said Ned cheerfully.  “Now I wonder, Obed, if the attack has been made on Texas.  Do you think we can yet get there in time?”

“I hope so,” replied Obed thoughtfully.  “You were a long time in San Juan de Ulua, but armies move slowly, and they have plenty of troubles of their own here in Mexico.  I would wager almost anything that no Mexican force in great numbers has yet crossed the Rio Grande.”