"It will be jolly fun to explore it," decided Ned. "I wish it wasn't so near night."
"We can't do much now," decided Tom. "It will be too dark, and I don't altogether fancy going in those old ruins except by daylight."
"Do you think any of those old Aztec priests, with their knifes of glass, will sacrifice you on a stone altar?" asked Ned, with a laugh.
"No, but there might be wild beasts in there," went on the young inventor, "and I'm sure there are any number of bats. There must be lots of nooks and corners in there where a whole army could hide. It's an immense place."
The ruined temple certainly was large in extent, and in its glory must have been a wonderful place. The balloon came nearer, and then Tom let it sink to rest on the sand not far from the ancient ruin. Out he leaped, followed by his friends, and for a moment they stood in silent contemplation of the vast temple. Then as the last rays of the setting sun turned the white stones to gold, Tom exclaimed:
"A good omen! I'm sure the city of gold must be near here, and in the morning we'll begin our search for the secret tunnel that leads to it."
"That's the stuff!" cried Ned enthusiastically.
An instant later it seemed to get dark very suddenly, as it does in the tropics, and almost with the first shadows of night there came a strange sound from the ruined temple.
It was a low moaning, rumbling sound, like a mighty wind, afar off, and it sent a cold shiver down the spines of all in the little party.
"Good land a' massy! What am dat?" moaned Eradicate, as he darted back toward the balloon.