“And they are about ten to our one,” put in Jerry. “But we’ve got to do something,” he added, seriously.

“Then we’ll start as soon as we can get in shape,” decided the professor. “I have a better plan than making a direct attack on the camp of the Mexicans, however. We will go to the authorities and ask their aid. Maximina says there is a detachment of soldiers stationed about thirty miles from here and on the line we must take to go to the camp, from which they are distant about ten miles.”

“Bully!” cried Ned. “With a few soldiers to help us we’ll give those brigands and Noddy Nixon such a licking that they’ll never want another.”

The automobile was soon made ready. In it was packed all that remained of the provisions. The professor did up his precious specimens and curios, not forgetting the lead casket of jewels.

The water tank was filled. Fortunately, there was still plenty of gasolene left. Jerry and Ned pumped up the tires, Maximina was invited to a seat in the rear, with the professor, and the travelers, taking a last look at the underground city, started off.

They went through the tunnel, up the incline, the fall of which had precipitated them into the shaft, and soon were on the level road, speeding to the rescue of Bob.

After Vasco had secured his captive, following Bob’s and Maximina’s flight, the brigand took measures to insure that the prisoner would not get away again. Bob was placed in a regular dungeon, and outside the door was stationed a man with a gun.

The poor lad was in low spirits. He began to give up hope, and the only thing that cheered him was the thought that perhaps Maximina might have gotten away and would notify his friends or the authorities.

But Bob knew it was a remote chance, for he did not believe the frail girl could stand the long journey alone. He tried to learn something about her; whether she had been recaptured or not; but to all questions his guard, and the old woman who brought him food, returned but one answer, and that was:

“No spik Inglis, señor.”