The strange happenings of the night formed the only topic at breakfast, and then the boys set off for town to get in communication on the telephone with the bungalow owner.
“I can’t see why he would object,” said Jack.
“Unless he made that passage for his own use, and doesn’t want any one to meddle with it,” Paul remarked.
“What could he use it for?” asked Walter.
“Well, that may be part of the mystery. Let’s take a short cut to the village,” and he indicated a path that led toward the cave in the mountainside.
They emerged into a country road, thick with dust, and were trudging along this, talking on all the aspects of the queer discovery, when Jack suddenly stopped and stared intently at something in the dirt of the highway.
“What is it?” asked Walter. “A snake?”
“No, marks of an automobile tire,” Jack answered.
“Nothing very remarkable in that,” laughed Paul.
“There is in this one,” Jack declared excitedly. “See the big Z mark where the tire has been patched—vulcanized. Boys, that’s the same mark as was on the tire of Cora’s car! I believe her machine has been along here this morning!”