At the same instant a fusillade from the rear of the house gave evidence that the men stationed upon the wall had done their work.
CHAPTER XXVIII.
BILLIE MAKES A DISCOVERY.
Having released Lieut. Grimes and taken the plotters into custody, the next task was to locate Strong, the mountebank, and to solve the mystery of the box.
Outside the one exclamation which Donald had uttered when he recognized Strong as the third of the plotters, he had not betrayed his secret to any one, and when Lieut. Grimes told his story to Gen. Funston and described the American, Donald vouchsafed no information which might help to apprehend him.
"The plotter told the Mexicans that he could be found at the Hidalgo Hotel whenever he was wanted," explained Lieut. Grimes. "While he may have lied about it, I think we should send a force and try to locate him."
The advice was acted upon and a corporal and four soldiers sent to the hotel, but to no purpose. No such man was known there.
"What was the use of my saying anything about it?" asked Donald of the other two boys when he returned to Santiago's house and narrated to them the story of his evening's adventure. "I was sure he was not there and I have no idea where he is; but we'll find him and the ten thousand dollars given him by the Mexicans for his treachery."