"How large a bill was it?" asked Adrian.
"Only a peso"—that is a dollar—"and it seemed hardly worth talking about; but you'd have thought it was a hundred."
"Perhaps it seemed a large amount to him," ventured Billie.
"Perhaps," admitted Don Esteban. "But be that as it may, I should like to see the man again, and especially would I like to know where he got that old dollar."
"Why?"
"Because it may have come out of that box."
"Well, yes," said Donald, with a shake of his head, "it might have; but how could the mountebank have gotten the box?"
"That is the mystery," was Don Esteban's reply.
"And how do you wish us to help you?" asked Adrian.
"Why," explained the banker, "I asked Gen. Funston to find the mountebank for me. He said you boys would do better than any one else."