DONALD IS KIDNAPED.

"Great Scott!" was the spontaneous exclamation of both the newcomers. "Where did it come from?"

"You tell," replied Billie. "Lucia says it was not here an hour ago. Neither has any one been in the room so far as she knows."

"Has she been here all the time?" asked Adrian.

"No, she was with Josie in her room for a time; but the door into the patio was locked."

"Some one might have come in through the window."

"A fat chance, isn't there!" laughed Billie, pointing to the only window in the room which was protected with long and heavy iron bars, set so closely together that a child would have had trouble in squeezing through—much less a man.

"Does look a little difficult," replied Adrian.

"Worse than difficult. Impossible," was Donald's comment.

"Did you hear any noise?" asked Billie of Lucia.

"None whatever."

"And you have never seen the box before?"

Lucia wrinkled her brows and thought deeply.

"Do you know," she finally said, "I have a sort of a dim recollection that, away back in my childhood somewhere, I have seen it or one just like it."

"Away back in your childhood," laughed Donald, "couldn't have been so very far, Señorita."

Lucia made a little grimace.

"I'm nearly seventeen," she said.

"Botheration!" said Billie. "We are not here to discuss ages, but to find out how this box came here. I have no doubt that Lucia has seen many similar boxes in her time."

"Well," asked Donald, somewhat nettled, "what do you propose to do?"

"In the first place, I want to search the house."

"That's a good idea," declared Adrian. "Donna Lucia, will you lead the way?"

"Certainly. Right this way; but don't go into father's room. I know there is no one in there. One of the servants has been with him every minute of the time."

Headed by Lucia, the boys explored the house from top to bottom, but not a sign of any one could they find. So far as they could determine, the box must have come in of its own self.

"I'll tell you one thing we can and must do," said Billie, after they had returned to the library. "We must keep a watch in this room to-night. Whoever put the box here may return."

"Right!" from Don. "You do have occasional lucid intervals, Billie."

Billie grinned, but made no reply.

"I think we may all stay here for a few hours," suggested Lucia. "Father is so much better that I think we may have a little music. I will play some accompaniments on the guitar and Josie can sing."

"That will seem a good deal like being back in the States," declared Adrian. "With the Stars and Stripes flying over my head, a brigade of American troops on guard and an American girl singing, I can almost forget I am on Mexican soil."

"How about the accompanist?" queried Billie.

"Oh!" laughed Adrian, "we're quite willing to adopt her. Hey, Donald?"

"Don't ask me, Ad. Ask Billie."

"I am sure we could do no better," was Billie's gallant reply.

Lucia's suggestion was carried out and for a couple of hours there was a merry little party under Santiago's hospitable roof. Even the mysterious box was forgotten and the young people were giving themselves up to a jolly good time, when suddenly there came a scream which caused every one to turn their eyes toward the room in which the sick man was supposed to be lying.

But there in the doorway he stood, his long night robe reaching nearly to the floor and his thin black hair standing almost on end.

"Father!" cried Lucia, rushing toward him "What is it?"

He waved her off, but made no reply, while with his long bony finger he pointed at the brass-bound box.

"Where did it come from?" he asked in a shrill, querulous tone. "Who brought back my secret casket?"

"Yours?" came from every one in the room.

"Yes! Mine! Mine!!" he almost screamed.

"He's raving!" cried Josie. "Can't some one do something for him?"

"No," he replied, and his voice became more calm, "I am not raving. I know whereof I speak. Quick! Let me look within it to see that all is safe."

"It is locked, Father," said Lucia, coming to his side, "and we have no key."

"I can unlock it," he cried. "I can unlock it. Give it to me. Give it to me."

He staggered forward and seized the box in his hands. For several seconds he fumbled with it, turning it first upon one side and then upon another, and at last raised the lid. He thrust in his hand and then stopped as one stupefied.

"Empty! Empty!" he gasped in an almost audible whisper. "The plan of Montezuma's mine is gone! Gone!!"

A moment he stood and gazed around upon the faces of those in the room and then collapsed upon the floor.

Quickly the boys picked him up and carried him to his bed and the attending physician was summoned.

Billie picked up the box and examined it curiously.

"I wonder how he opened it?" he mused. "There must be some sort of a spring somewhere."

He felt the box all over, but could find nothing. Then he closed it and set it upon the table. A moment later Donald picked it up and tried to open it, but it was locked fast.

"Nothing but mysteries," he said. "I'm getting tired of them. But before anything else happens, I'm going around and notify Don Esteban that the box is here."

"I'll go with you," said Adrian.

"No, you'd better stay here. I'll take a mozo with me."

He ran hastily down the stairs and a minute later the boys heard the gate close behind him.

"I guess this is the quickest way," thought Donald as he gained the sidewalk. "I'll not bother with a mozo. With American soldiers on guard and my automatic in my pocket, I have nothing to fear."

A couple of minutes later he was ringing the bell at Don Esteban's house. He was hastily admitted and at once conducted to that gentleman's presence, where he narrated hastily what had occurred at the other house.

"Who is this old man?" Don Esteban asked of Donald.

Donald explained as best he could.

"Which is mighty little," he declared when he had finished. "He is the greatest mystery we have ever encountered. There is no doubt that he is an Indian, but he speaks English like an Englishman."

"I must go and see him at once," declared Don Esteban, rising.

"I don't think you can, sir, to-night. I don't think the physician would permit it."

"Well, then, the first thing in the morning. I thank you, young sir. Won't you have a glass of wine before you go?"

"No, I think not," replied Donald. "I've never acquired that Mexican habit yet. Good night, sir."

He left the house feeling greatly relieved that he had reported the finding of the box and walked slowly along whistling merrily. As he turned off the street upon which Don Esteban lived he heard soft footsteps behind him and turned hastily.

But he was too late.

Before he could see who it was, or ere he could cry out, a cloak was thrown over his head and he was picked up and carried away bodily.

Donald was not the boy to give in without a struggle, but kick and squirm as he might, he could not free himself. Presently those who were carrying him stopped and laid him on the sidewalk. Then he heard a knock and a gate opened. Then he was lifted up again and, almost before he knew it, he was thrust into a little room—a closet it seemed—and the door closed upon him.

It was a hot night and the little place was stifling.

"I'll smother if I don't get out of this," he muttered.

Slowly he unwrapped the cloak from about his head and at last freed himself completely from its folds; but he secured little relief from the heat.

The room could not have been more than six feet square and it did not take Donald long to run his hand clear around the wall.

There was only one door, that through which he had been thrust, and it was locked. He pounded upon it, but to no avail. Then he sat down to think.

"There is certainly no use to sweat myself to death," he told himself. "I'd better be as quiet as I can. There is air enough coming under the door so I won't suffocate, so I might just as well wait and see what will turn up."

He ran his hand all over his automatic and found it in good shape. Then he leaned back against the wall opposite the door and waited. Ten minutes later the door was suddenly yanked open, another figure was bundled into the closet and the door slammed shut, almost before Donald could think.


CHAPTER XXVI.