CHAPTER XXIV.

  DON ESTEBAN'S STRANGE LOSS.

  "Before I explain to you the mission I wish you to undertake,"said Don Esteban, "I must narrate briefly a story that has beenhanded down from the days of Montezuma. It is to the effect thatwhen the Spanish conqueror, Cortez, was about to capture the Cityof Mexico, most of the treasure of the Aztecs was sunk in thelake, which at that time covered a portion of the Mexicanplateau.

  "A part of this treasure is said to have been recovered, but themine from which the gold of Montezuma was taken has never beendiscovered, although search has been made for upward of fivehundred years. Some have supposed that the mine was adjacent tothe City of Mexico and that it was flooded at the time thetreasure was sunk in the lake. Others have thought it was locatedin the state of Michoacan, while still others have believed itlocated in the vicinity of Mt. Orizaba.

  "My reason for telling you this is that some years ago a strangeappearing man came to our bank and made a large deposit of money,all in gold. He did not deposit it all at once, but brought it ina few thousand dollars at a time until it amounted to more than amillion dollars. Then he disappeared and we have never seen himsince."

  "And has he never called for any of the money?" asked Billie.

  "Not in person, although he has drawn upon it at frequentintervals. The name under which it was deposited is James Moon."

  "An American?" asked Donald.

  "I could not say whether he was an American or an Englishman. Wetook him for the latter. But now I am coming to the real part ofthe story.

  "In addition to the money which he deposited, he also left withus a small brass-bound box, in which he said there were valuablepapers. He gave orders that it should be delivered to no one buthimself in person, or until the expiration of ten years. The tenyears will be up in a few days and this afternoon I bethought meof the box. But when I went into the vault in which it has beenkept for so many years, the place upon an upper shelf, where ithas always stood, was vacant. The box was gone!"

  "Gone?" exclaimed all the boys in unison. "Do you mean stolen?"

  "So it would appear."

  "How could it have been done?" asked Adrian.

  "I cannot say; but the strange thing about the whole matteris that in place of the box, there lay upon the shelf anenvelope--yellow with age, upon which was written in ink that hadscarcely faded the words: 'Montezuma's Mine.'"

  "Well, what do you think of that?" queried Billie, looking at theothers in amazement.

  "I don't think," laughed Adrian. "It's up to you to do thethinking."

  "Is there no clue whatever?" asked Donald.

  "Not that could be really called a clue. The only suspiciousthing that has happened to-day at all, was that a mountebank cameinto our bank----"

  "A mountebank!" from all.

  "Yes."

  "Did he have an ape with him?"

  "No! He was quite alone. He did not come in to make merry, but toget a bill changed. While he was there he was observed toscrutinize the place very closely."

  "But he did not go into your vault?"

  "No! He took his change and went peaceably out."

  "Then, why should you suspect him?" insisted Donald, casting aknowing glance at the other boys.

  "Because, an hour later, he came in again and said that one ofthe bills we gave him as change was a counterfeit."

  "Was it?"

  "No, it was not, although it was an old issue. The teller whowaited upon him had no recollection of ever having seen the billbefore, but rather than have a scene, we gave him another billfor it."

  "How large a bill was it?" asked Adrian.

  "Only a peso"--that is a dollar--"and it seemed hardly worthtalking 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 shouldlike to see the man again, and especially would I like to knowwhere 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 mighthave; 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 themountebank for me. He said you boys would do better than any oneelse."

  "But why us? Why not a Mexican policeman?"

  "Because the mountebank was an American. He may even have been asoldier and have hidden himself among your men."

  "Oh, he was an American, was he?" laughed Donald. "Then I believewe can put our finger on him with ease. But the man we have inmind always carried with him an ape."

  "Then it may not be the same," replied Don Esteban, "for this onehad no ape with him either time."

  "It certainly does look like a mystery," was Adrian's comment."Where is the vault from which the box was taken?"

  "On the other side of the patio."

  "May we examine it?"

  "Certainly. I'll show it to you now."

  Don Esteban led the way downstairs and across the patio. Openingthe rear door of the bank, he escorted them within and closed thedoor.

  Passing behind the counter, he opened the iron door of the vault,disclosing within a good-sized chamber, in the rear of which wasset the great steel safe, locked with a time lock.

  "There," explained Don Esteban, pointing to an upper shelf, "iswhere the box stood."

  "Oh, it was not a large box, then!" said Adrian.

  "Oh, no! Not more than eight or nine inches cube."

  The boy examined the vault carefully by the light of a gas jet.

  "There seems no way that any one could have entered except by thedoor," said Donald.

  "None whatever!"

  "You are sure there is no opening in the ceiling?"

  "Absolutely."

  Don Esteban led the boys out and locked the door of the vault.

  "Well," declared Donald as they came out into the patio afterfinishing their inspection, not only of the vault but of the restof the office, "I guess we had better go home and study over thematter a little. I should not be surprised if we could put ourhands upon the mountebank with very little trouble; but I feelsure he had nothing to do with the disappearance of the box."

  "I wish I could feel that way," said Adrian after they were outof hearing of Don Esteban. "I have never quite trusted Strong.There is something strange about him."

  "Yes, he is a bit queer; but how on earth could he have stolenthe box if he did not even go behind the counter?"

  "He couldn't; but still I mistrust him."

  "I wonder where Ambrosio was all this time?" mused Billie.

  "Tied up at home, most likely. An American among Americans wouldhardly feel like traveling around with a hand organ and amonkey," was Don's emphatic reply.

  Upon arriving at Santiago's residence they were told thatStrong had been there earlier in the evening and seemed muchdisappointed at not finding them at home.

  "Did he leave any word?" asked Billie of the portero.

  "None, senor; but Donna Lucia would like to see you in thelibrary."

  "What is the matter? Is Santiago worse?"

  "No, senor. He is sleeping quietly. I could not say what shewants, but she seemed considerably disturbed."

  "Better go up alone, Billie," said Donald. "If we are needed, youcan call us. We'll wait here in the patio for a few minutesbefore we turn in."

  Billie ran up the stairs and tapped at the library door. He wasimmediately admitted by Lucia and the door was closed behind him.

  "It is getting to be a good deal of a family affair," laughedAdrian.

  "Yes," replied Donald, with a grin. "I wonder where Josie and Mr.Black are?"

  Adrian colored.

  "I don't know why you should have thought of them!"

  "Oh," replied Donald nonchalantly, "speaking of family
affairsnaturally reminded me that you----"

  "Oh, Don!" came Billie's voice, breaking in upon theconversation.

  "Yes. What is it?"

  "Come up here, the both of you! Quick!"

  The boys ran up the stairs two steps at a time.

  "In here," and Billie held the library door open. "I've somethingI want to show you."

  He led the way to the table, and there, under the glow of thelamp, stood a brass-bound box about eight or nine inches cube.