"Better go up alone, Billie," said Donald. "If we are needed, you can call us. We'll wait here in the patio for a few minutes before we turn in." Billie ran up the stairs and tapped at the library door. He was immediately admitted by Lucia and the door was closed behind him. "It is getting to be a good deal of a family affair," laughed Adrian. "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 affairs naturally reminded me that you----" "Oh, Don!" came Billie's voice, breaking in upon the conversation. "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 something I want to show you." He led the way to the table, and there, under the glow of the lamp, stood a brass-bound box about eight or nine inches cube. CHAPTER XXV. 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, Senorita." 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.