Springing from his horse, he ran up the track waving the red signal as he ran.
A sharp blast from the whistle a couple of minutes later gave proof that the danger signal had been seen, and the grinding of the brakes told that the train was coming to a stop. Even before this was an accomplished fact the conductor swung himself from the front car and came running down the track to see what was the matter, while the guards covered the boys with their carbines.
"What do you mean by stopping the train?" he demanded angrily.
Donald explained in as few words as possible.
The conductor signalled the guards to him and told them what Donald had said.
"What had we better do?" asked the conductor.
"We had better go back to Pachuca for help," replied the guards.
"And let the Zapatistas escape!" exclaimed Billie hotly. "What do you want to do that for?"
"We have only six guards," the conductor explained, "and——"
"And that, with us, makes ten," interrupted Billie.