CHAPTER XXVIII.
BOB IS TAKEN PRISONER.
They now felt thoroughly at home on the mountain top, and set a straight course for the Dark Cave.
It promised to be an exceedingly warm day, and they had not proceeded far before all were bathed in perspiration.
"This is too bad," observed Don. "We won't want to go underground while we are so hot. We may get a chill."
"We can rest awhile at the entrance to the cave," said Robert Menden. "We'll need it before climbing over the rough rocks to where that crack is located."
Reaching the entrance, they threw themselves on a grassy bank in the shade to rest.
Although they did not know it, Joseph Farvel was close at hand, and now watched them intently.
The fellow felt that they had discovered something, and wished to ascertain, if possible, just what it was.
"I'll dog them; see if I don't," he said to himself.
