The next instant a high-pitched voice came booming down the tunnel.
“S-s-s-s-say this bub-bub-beats the Sub-ub-ub-ubway!”
“Jumping hop-toads! That’s Ding-dong Bell!” cried Joe, dashing down his hammer.
“And the professor!” cried Nat as another familiar voice came toward them.
“And Mr. Tubbs! What on earth!”
With wild whoops of joy the two boys who an instant before had been expecting to face, they knew not what, peril, rushed to meet their friends. They were in such a hurry that they narrowly escaped being shot, the other party being as much alarmed at their approach as they had been at the advance of the professor and his companions.
Matters were soon explained. The professor and his comrades had found the mouth of a tunnel in an old temple. Entering this, it had brought them underground. Some distance above the lake end of the tunnel which the boys had traversed, the passage by which the professor had travelled joined it. The hurry of Nat and Joe to reach the fresh air explained why they had not noticed the branch passage. Had they done so and followed it they would have come out not far from camp.
CHAPTER XVII.
“DID WE DREAM IT ALL?”
The search of the ruins was prosecuted with vigor for several days more before they stumbled upon anything in the way of “te-ter-treasure,” as Ding-dong Bell called it. But during that time the boys’ eyes had been so satiated with wonders of ancient architecture and carvings, that they had almost forgotten about the more material part of their quest.