CHAPTER XXI.

NODDY HAS A TUMBLE.

When Vasco and Noddy, foiled in their attempt to kidnap Bob, retreated through the forest, they went into camp with their crowd in no very pleasant frame of mind. The Mexicans whom Vasco had hired to assist him were angry at being foiled, and they talked of deserting.

"Go on, if you want to," said Vasco, carelessly rolling a cigarette; "so much the more gold for us when the rich man ransoms his son."

This was enough to excite the greed of the men, who talked no more of going away.

The next day, after a consultation, Noddy and Vasco decided to continue on the trail of the boys and the professor. They pursued the same tactics they had previous to the interrupted kidnapping, and were careful not to get too close to those they were trailing.

All was not harmonious among the members of the band with which Noddy had surrounded himself. The men had frequent quarrels, especially when they were playing cards, which they seemed to do when they were not smoking cigarettes.

After dinner one day the Mexicans appeared to be much amused as they played their game. They laughed and shouted and seemed to be talking of the automobile, for Noddy had brought his machine up to the camp of the horsemen.

"What are they talking about?" asked Noddy of Vasco.

"They are making a wager that the one who loses the game must ride, all by himself, in the automobile," replied Bilette.

"But I don't want them to do that," said Noddy. "They don't know how to run the car."

"That's the trouble," went on Vasco. "No one wants to lose, for they're all afraid to operate the machine. But if one of them tries to do it, you'd better let him, if you don't want to get into trouble."

With a shout of laughter the men arose from where they had been playing the game. They seemed to be railing at one chap, who looked at the auto as if he feared it might blow up and kill him.

"You're in for it," remarked Vasco. "Whatever you do don't make a fuss."

With a somewhat sheepish air a young Mexican, one of Vasco's crowd, came near the auto. He made a sign that he wanted to take Noddy's place. The latter frowned and spoke in English, only a word or two of which the native understood.

"You shan't have this machine," spoke Noddy. "It's mine, and if you try to run it you'll break it."

But the Mexican paid no heed. He came close up to Noddy, grabbed him by the collar and hauled him from the car. Noddy was the only one in it at that time, Berry, Dalsett and Pender having gone off a short distance.

"Let go of me!" cried Noddy, trying to draw a small revolver he carried.

The Mexican only grunted and retained his grip.

"If you don't let me alone I'll fire!" exclaimed the youth. He had his revolver out, and the Mexican, seeing this, allowed his temper to cool a bit. But there was an angry look in his eyes that meant trouble for Noddy.

"Now you fellows quit this gambling," commanded Vasco. "We'll have hard work ahead of us in a little while, and we don't want any foolishness. Leave Noddy alone. Don't you know if any one tries to run that machine that hasn't been introduced to it, the engine will blow up!"

"_Diablo!_" exclaimed the Mexican who had lost at cards and who was about to attempt to operate the auto. "I will let it alone!"

Quiet was restored, but the bad feeling was only smoothed over. It was liable to break out again at any time. The main object of the crowd was not lost sight of, however, and every hour they drew nearer the trail of those of whom they were in pursuit.

As it grew dusk, on the day of the quarrel over the auto, Noddy and Vasco, with their followers, came to a small clearing. They decided to stop and have supper.

"If I'm not mistaken, the other auto has been here within a short time," remarked Vasco, pointing to marks in the sandy road. "And there seem to be footprints leading over there through the underbrush."

He followed the trail, and came to the place where, a short time before, Professor Snodgrass had battled with the cocoanut-throwing monkeys.

"Looks as if some one was going to start in the wholesale business," went on the Mexican, glancing at the pile of nuts the simians had piled up.

"Do you think we are close to them?" asked Noddy, for, since the experience of the afternoon, he was anxious to get the kidnapping over, and be rid of the Mexicans.

"They have been here very recently," said Vasco.

"How can you tell?" asked Noddy.

"See where the oil has dripped from their machine," replied Bilette, pointing to a little puddle of the lubricant in the road. "It has not yet had time to soak away, showing that it must have been there but a short time, since in this sand it would not remain long on top."

"Shall we go on after them or camp for the night?" asked Noddy, following a somewhat lengthy pause.

"Keep on," replied Vasco. "No telling when we may get another chance. Get the boy when we can. We'll have to do a little night traveling, but what of it?"

Noddy assented. He spent some time after supper in oiling up the auto and getting the lamps filled, for darkness was coming on. Then, all being in readiness, Noddy started off, the horsemen keeping close to him.

For a few miles no one in the party spoke. The auto puffed slowly along, the horsemen managing to keep up to it.

"How do we know we're on the right road?" asked Noddy at length. "We may have gone astray in the darkness."

Tom Dalsett took a lantern and made a careful survey of the highway. He came back presently.

"We're all right," he said. "There are auto tracks just ahead of us. We may come up to them any minute now."

Once more Noddy's auto, which he had stopped to let Dalsett out, started up. The pace was swift and silent. But as they penetrated farther and farther into the depths of the forest there was no sign of the boys and the professor, who, by this time, were in the underground city.

"I don't believe we'll find them," spoke Jack Pender. "Let's camp now and take up the trail in the morning, when you can see better."

"No; we must keep on," said Vasco, firmly. "It is to-night or never. I can't hold my men together any longer than that."

Off into the darkness puffed the auto. The men on horseback followed it, the whole party keeping close together, for several jaguars were seen near the path, having been driven from their usual haunts because of the scarcity of game.

Every one was on the alert, watching for any signs of the travelers they were pursuing. Every now and then some one would get out and examine the road to see if the auto marks were still to be seen. They were there, and led straight on to the hidden city.

It was some time past midnight and the machine was going over a good patch of road, when Jack Pender, who was seated beside Noddy, suddenly grabbed the steersman's arm.

"What's that ahead in the road?" asked Jack.

"I don't see anything," replied Noddy. "It's your imagination. What does it look like?"

"Like a big black shadow, bigger and blacker than any around here. Can't you see it now? There it is! Stop the machine, quick!"

Noddy, peering through the gloom, saw what seemed to be a patch of shadows. He gave the levers quick yanks, jammed down the brakes and tried to bring the machine to a stop.

But he was too late. With a plunge the car sank through the earth and rushed along the inclined plane down which Jerry and his friends had coasted a few hours before. There were wild cries of fear, mingled with the shrill neighing of horses, for some of the riders and their steeds also went down the trap that had been laid.

The auto remained upright and shot along the floor of the tunnel to which it had fallen, undergoing the same experience as had the machine of Jerry and his friends.

Then, with a crash that resounded through the confines of the ancient city, Noddy and his machine and all who were in it brought up against the massive door closing the tunnel, which portal Jerry had swung shut after he and his friends had passed through. Following the crash there came an ominous silence.