“What is it, Jack, a big rock?”
“Rock? No! Look over those tree-tops; don’t you see that thin column of smoke rising high into the air and as straight as a church spire?”
“Gosh! yes. What of it? There can’t be much wind.”
“It is a signal of the bush-raiders.”
“S’pose it is?”
The train was now winding through the valley of the Rio Tasma, and the sullen roar of the mountain stream was beginning to be heard above the thunder of the cars, which were rushing along at a rapid rate.
“I am sure of it,” replied Jack, as he continued to watch the ascending smoke, though without neglecting his survey ahead. “What else can it mean?”
“Sure enough.”
“Do you think we have a brakeman we can count on in case of an attack?”
Plum hesitated a moment before replying.