Free The Jungle Pyramid by Franklin W. Dixon

Maximilian, who ruled Mexico during the American Civil War.
    â€œWhat happened to Emperor Max?” Joe asked.
    â€œWe shot him,” Juan said laconically.
    They climbed up to the roof garden for a view of Chapultepec Park. Frank turned his head. A man with gray hair, wearing a dark suit, was on the other side of the garden. He held a briefcase! Frank tapped Joe on the shoulder and pointed.
    â€œZemog!” Joe gasped.
    The brothers pushed through the crowd, turning and twisting in the press of bodies. At one point they were stopped by a solid wall of visitors and had to detour around them. Struggling and panting, they inched forward. At last they got to the other side.

    â€œI see much gold!” the woman said.
    The suspect was gone!
    Frank and Joe hurried through the rest of the castle, only to draw a blank in every hall. They ran out to the terrace. Zemog was not there either.
    â€œThis is getting ridiculous,” Joe fumed. “Zemog pops up in the craziest places, and when we follow him, he dissolves into thin air!”
    â€œWe let him escape again, as Orlov would put it,” Frank agreed. “Which isn’t saying much for us!”
    â€œI’m beginning to think it’s Zemog’s ghost who’s giving us this problem.” Joe chuckled.
    The boys strolled around the terrace until they found Juan and their friends.
    â€œWhat happened?” Biff asked. “You took off so fast we didn’t even have a chance to offer our help!”
    â€œWe think we saw Zemog again,” Frank explained. “And as usual, he escaped.”
    â€œWhat do we do now?” Chet asked.
    â€œI think we should finish our sightseeing tour at police headquarters,” Joe suggested.
    Everyone agreed, and Juan took them to their destination. The boys thanked him for the tour, paid him, and went inside.
    The sergeant at the desk spoke English well and listened to their problem with interest. He checked his records for Zemog, but found nothing.
    â€œZemog is not a Mexican name,” the sergeant said. “Unless he uses an alias, we should be able to track him down without too much difficulty. I will check all the hotels and see what I can learn.”
    The boys returned to their hotel for the night. After breakfast the next morning, they taxied to the university to meet Carlos Alvarez. The professor’s office was lined with rows of books on archaeology.
    He identified Palango at once. “It is an archaeological site not far from the great ruins of Chichén Itzá on the peninsula of Yucatán. Palango was recently discovered and digging has just begun. It lies in the same area as a lost pyramid of the Mayas. Fifty years ago a hunter reported seeing the pyramid. But since then, every attempt to find it has failed. What is your interest in Palango?”
    Frank said that somebody might have flown gold from Mexico City to Palango.
    Alvarez was puzzled. “I don’t know why anyone would do that. Usually it is the other way around.”
    He gave them a little lecture on gold, noting that the Aztecs molded it into fine art pieces. “Their artifacts are so good many people cannot tell the difference between Aztec and Scythian.”
    Chet puffed out his chest. “Oh, I can always tell Aztec stuff!” he boasted.
    Alvarez smiled. He took a small piece of gold representing the head of a child from his drawer. “What do you make of that, my friend?”
    Chet hefted the gold in his hand. “That’s Aztec, all right.”
    â€œNo, it comes from the Inca civilization down in Peru,” Alvarez corrected him.
    Chet turned red in the face. His companions snickered, but Alvarez was indulgent. “An easy mistake to make.” He soothed Chet’s feelings.
    That ended the session with the professor. The boys, deciding to run down the Palango angle at once, went to the airport and chartered a plane to fly them to Yucatán.
    Three hours later they were