"Just a few minutes more," he began, "and I'll go with you to see Dr. La Vega-"

Biff interrupted to say that Dr. La Vega was being brought to the hotel and as Mike added details of the cave-in, Bortha's eyes went wide with alarm. He hurried from his room to meet the stretcher bearers as they entered the patio. Mrs. Brewster arrived to say that the hotel was sending for the village doctor, and Mr. Brewster commented: "Good. Dr. La Vega has already become partly conscious, but he must be kept quiet until we know how seriously he is hurt."

They placed Dr. La Vega in a bedroom, and Mrs. Brewster, who was an experienced nurse, took charge of the patient. In the patio, the twins listened breathless while Mr. Brewster related all that had happened in a style that was all the more dramatic because it was simply told.

72 .

Standing by were the workers, silent and stolid as if nothing had happened. It seemed that nothing could disturb them until Professor Bortha turned to them with a puzzled expression and asked: "But how did you manage to escape the cave-in? You were at the inner end of the tunnel when it happened-and if it happened so quickly-"

The workers interrupted with an excited babble in their native dialect, until Chaco quieted them and became their spokesman. He turned to Mr. Brewster: "Ten, fifteen minutes after you left us-maybe more-the lights went out, very sudden. We heard a voice, saying, "Go-go quick! p.r.o.nto! On came the lights again, and there he was-you remember where we had been digging, Senor? Right there he stood."

The babble rose again, the usually stolid workers reaching a high pitch of excitement as Chaco continued: "He was wearing the face with all the jewels- green and blue-with the big stone that shines like fire, here"-Chaco tapped his fingers against his chest -"and he was pointing this way, with the big knife"-Chaco extended his hand-"telling us to go-"

The other voices now were drowning Chaco's as his excited companions shouted with new frenzy: "Tizoc! He tell us, 'Go-or you will die!' So we go! Tizoc has saved our lives!"

CHAPTER IX.

At the Sign of the Bull ANOTHER hour had pa.s.sed. The native workers had left the Hotel Pico, all except Chaco. He was waiting to hear the report of the village medico, who had arrived in the meantime and was now probing the extent of Dr. La Vega's injuries.

But before they had left, the workers, to a man, had repeated Chaco's story of the appearance of Tizoc, with added descriptions that were complete in every detail.

Unquestionably they had met the same jewel-masked, gold-robed figure that Biff and Mike had encountered in the Arista mansion. As final touches, he had been wearing the matchless fire-opal and brandishing the unique obsidian knife-Tizoc's symbols of authority.

Professor Bortha had questioned the workers nar-

73.

74 .

rowly on all those points, using their own native dialect, a carry-over from the Aztec days. Now, Bortha summed it: "Whoever the man was, he must have been wearing the stolen Tizoc costume. Someone must have brought it here from Mexico City."

"That would not have been difficult," observed Mr. Brewster. "But how did this impostor manage to get in and out of the excavation? Is there another pa.s.sage leading there?"

"None that I know," returned Bortha. "What puzzles me is how Tizoc caused the collapse of the tunnel, timing it so exactly."

"That was simple enough," said Mr. Brewster. "The shorings, though strong, had been so arranged that if a few were knocked away, the rest would go. But Tizoc still needed a way out for himself and the men who helped him."

"You mean he needed helpers?"

"Absolutely. It was too fast for a one-man job unless a heavy explosive charge was used. In that case, I would have noticed the shock in La Vega's cabin."

Biff knew that his father, through long training as an engineer, could sense a slight blast, even at a great distance. He whispered that fact to Mike, who was seated beside him in the hotel patio, both listening eagerly to all that was said.

"There is one man," declared Bortha slowly, "who AT THE SIGN OF THE BULL 75.

knows a lot about mining operations. That man is Justin Kirby, who is reviving the old mines in the valley. He knows a lot about our excavation work, too"-Bortha set his straight lips rather grimly-"because he has been steadily stealing our workers."

"By offering them better wages?" asked Mr. Brew-ster.

"At first, yes," Bortha replied. "Then came all this Tizoc talk. Kirby could have been behind that. When workers said they saw Eagle Knights moving in and out of the excavation, they could have been some of Kirby's crew, sent to scare our men. I don't think he can afford to pay high wages any longer."

"Because he is running short on funds?"

"Yes. He sends out shipments of silver by mule train, over the trail behind this hotel; but when they come back with supplies and mining equipment they are less than half loaded. Now comes this Tizoc business-"

There was an interruption as the village doctor came from Dr. La Vega's room. He reported to Professor Bortha and Mr. Brewster: "The patient has a severe concussion, which has caused some lapse of memory. He keeps talking about some torn slips of paper, saying that he is sure that he can find them and that they will explain everything. I advise complete rest until his condition improves."

76 .

As soon as the medico had left, Bortha gave a puzzled frown and asked: "What could Dr. La Vega mean by torn slips of paper?"

"These." Mr. Brewster brought the four slips from his pocket. "I was looking at them when the cave-in started. So I held on to them. But there are five more that Dr. La Vega still had. They went in the landslide, along with the cabin and everything in it."

Bortha studied the slips that Mr. Brewster showed him. Bortha was prompt in his interpretation: "Hombre-man-that could be Kirby. Very probably, because the next slip says: Que plata-what silver or which silver-and Kirby is mining silver. And this one: Oro-gold, yes, Kirby wants gold, too. But Rojo-red-I don't see how it fits."

Ted and Monica had been listening, too. Now the twins were really in their element. To them, these slips were just another word game. They edged forward, and suddenly Ted exclaimed: "I see how it fits! Look, the slip with rojo fits right after the one that says oro. Oro rojo. Gold red!"

"Red gold," corrected Mr. Brewster. "That could mean copper. Kirby would be more likely to find old copper mines than gold mines."

"The Aztecs mined both gold and copper," commented Bortha, "but they paid little attention to silver. There may be more to this Tizoc game than AT THE SIGN OF THE BULL 77.

we realize. Kirby may be hoping that the natives here will lead him to old, forgotten mines."

"Where will we find Kirby now?"

"He has probably gone down to the valley. No wonder he dodged from sight at the landing strip this morning. He wouldn't want us to see him in El Cielo, while he was planning to pose as Tizoc." Bortha paused a moment, then added in a reminiscent tone: "In fact, Kirby has been avoiding me constantly. He used to stop here at the Hotel Pico and keep his mules in the corral out back. But when Dr. La Vega told him to stop influencing our workers, he walked out in an angry mood. Now he stops at a little posada or inn, down in the town. The 'Bull's Head,' they call it-or the 'Fighting Bull,' I forget which. It has a picture of a bull over the door."

"We can get back to Kirby later," decided Mr. Brewster. "Our first job is dig out that excavation and learn what caused the cave-in. Do you have a plan of the tunnels?"

"No, those were all in the cabin. But I have some rough diagrams which give the original measurements."

Bortha went to get them, and Mr. Brewster told Biff and Mike that there would be no need for them to stay. The boys strolled out through the front door of the hotel and stood there, looking down at the

78.

quaint town of El Cielo, with the vast valley yawning like a tremendous gulf below.

"Let's go down into the village," suggested Biff, "and look for that inn Professor Bortha mentioned."

"And look for Kirby, too?" laughed Mike. "Not much chance of finding him now; but anyway, let's go-"

AT THE SIGN OF THE BULL.

79.

They were starting down a steep path, with the roofs of the town so close that they seemed within a pebble's toss. But that was an illusion, caused by the fact that the town was so much nearer than the far reaches of the distant valley. At the end of a few minutes descent, El Cielo hadn't budged a foot.

Then, rather suddenly, the whole perspective *

80 .

changed. The slope of the ground was more gradual; the village seemed to rise and the valley began to lengthen. Over the tops of houses, Biff and Mike could see for miles to a huge ma.s.s of green between flanking mountains that faded gradually into a gray haze.

"Tropical foliage!" exclaimed Biff. "That valley must be more than a mile deep."

"About a day's ride down," calculated Mike, "and the same coming up. You have to take it slowly on muleback, with one foot dangling over the edge of a trail, a mile above nothing!"

"Then you'd have to start early to make it by dark?"

"I would say so, Biff. That's why they have a corral up at the hotel Pico. The hacienda was built where they made the first overnight stop on the trail. They had to put the mules up, too."

They had reached a back street of the village and were watching their footing on the rough cobblestones. But Biff's mind was still on the mule trail.

"If Kirby staged the Tizoc act over in the excavation," declared Biff, "he couldn't have made an early start down the trail to the valley. He'd still be staying over at the Bull's Head."

"Or the Fighting Bull," returned Mike. "We'll know which to call it after we see the sign. But you've got a good point there, Biff."

AT THE SIGN OF THE BULL 81.

Biff's immediate answer was, "Ouch!" as he almost twisted his ankle on a cobblestone.

"These streets have their points, too," he laughed. "But getting back to Kirby. Even if he has left the Bull's Head, maybe we can find out how long ago it was. One hour-two-"

Mike was nodding, as he looked along the narrow streets. He interrupted, suddenly: "You're right, Biff."

"About Kirby?"

"Yes. See there."

Biff looked along the street and saw a waddly mule, led by a native in white trousers, blouse, and sombrero. Hanging from the mule's flanks were big bunches of bananas and meshwork bags of hemp containing dozens of ripe oranges.

Biff was puzzled.

"What has that to do with Kirby?" he asked. "Kirby ships out silver and brings back mining equipment."

"It's all the same to a mule," replied Mike, "whether he carries bars of silver or bunches of bananas and bags of oranges. Both come from the valley. This man started early with his mule. They are just getting here now-"

"I get it," interrupted Biff, with a grin. "So Kirby is probably still here, as I thought."

"Yes. So now we find the Fighting Bull."

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They weren't long in finding it. The streets of El Cielo were steep, in fact so steep in places that they became steps cut in the cliff side. But those streets were short, closely meshed, and few in number. The buildings were mostly two stories in height, so from each corner, the boys could look over the block below, because it was one story lower.

As a result, they recognized the inn even before they saw its sign. Though no taller than the other houses, it was twice as long and three times as wide. Biff and Mike turned the corner and came to the low archway that formed the front entrance.

A lazy-looking fruit peddler was propped against the wall beside the archway, surrounded by bunches of two- and three-day-old bananas. He beckoned to the boys and waved a hand toward the bananas as though inviting them to buy. But they gave him only a brief glance.

They didn't even have to ask the banana seller if this was the town inn. Above the arched doorway was a crudely painted picture of a big, reddish bull charging head down as if to drive customers away.

The bull was mostly head, so the tavern could well be called the Bull's Head although the local artist had added a body, which was definitely undersized. That had enabled him to show the bull's front hoofs kicking up the ground, with its tail waving in a wild, menacing fashion, which cla.s.sified it as a fighting bull as well.

AT THE SIGN OF THE BULL 83.

But Biff and Mike weren't worried by such technical angles. They didn't even waste time talking to the banana man. Instead, they moved into the arched entry, where Biff whispered: "This is the place. What do we do now?"

"Wait here a moment."

As Mike spoke, two mariachis walked past the doorway. They were carrying small guitars and wearing low, narrow-brimmed sombreros with oddly decorated edges which matched the designs of their colorful sc.r.a.pes.

Apparently, both musicians belonged to the same troupe. They were talking to each other as they strolled by, and did not notice Biff and Mike. When the pair had pa.s.sed, Mike pointed to a pudgy, dark-faced man who was slouched behind a desk in the lobby, half asleep. Then he indicated a stairway, just beyond.

"I'll talk to the innkeeper," whispered Mike. "Start up the stairs and wait for me."

Biff reached the stairway while Mike was waking the man at the desk. He heard Mike ask for Sefior Kirby; then followed a conversation in Spanish, from which Biff gathered that the innkeeper was telling Mike that Kirby had gone out an hour before and might not be back until after dinner.

The word veinte-quatro was spoken back and forth, and from it, Biff decided that twenty-four was the number of Kirby's room. Biff moved softly upstairs 84 .

and was waiting near the door when Mike joined him. Biff motioned for silence.

"The door is partly open," he whispered, "someone may be in there."