"Let's eat," suggested Ned, "and then we four can circle around together." Tom agreed that this would be a good plan. A little later then, with Tom nearest the temple walls, the four began their march around them.
Four times that morning they made the circuit, and the same number in the afternoon, until they were nearly half a mile away from the ruin, but no tunnel showed.
"Well, we'll have to keep at it to-morrow," suggested Tom. "It's too soon to give up."
But the morrow brought no better success, nor did the following two days. In fact for a week they kept up the search for the tunnel, but did not come upon it, and they had now pretty well covered the big plain. They found a few ruins of the ancient city of Poltec.
"Well, what about it?" asked Ned one night as they sat in the balloon, talking it over. "What next, Tom?"
"We've got to keep at it, that's all. I think we'll go up in the balloon, circle around over the plain at just a little elevation, and maybe we can spot it that way."
"All right, I'm with you."
But they did not try that plan. For in the middle of the night Ned suddenly awakened. Something had come to him in his sleep.
"Tom! Tom!" he cried. "I have it! What chumps we were!"
"What's the matter, old man?" asked Tom anxiously. "Are you sick--talking in your sleep?"