"Better! He has gone to sleep, and if he is not disturbed, I expect him to be greatly improved when he awakens. I should not be surprised if this were the turning point in his illness." "Then we had all better go down on to the first floor and leave him alone with his nurses." "I'd give a good deal to know where Strong is," remarked Donald as they were drinking their coffee an hour later. "So would I," declared Billie. "I believe, if we can find him, we can solve this entire mystery." "As soon as we finish our coffee," suggested Donald, "let's get busy and find him. He can't be far." "That's right," said Adrian. "We'll round him up in short order. Hey, Billie?" "We ought to; but I'll tell you what. You fellows go out and see if you can get a line on him, and I'll hang round the house to see that the devil doesn't come and steal the rest of the house." "Especially Lucia," laughed Donald. "That's all right," was the good-natured reply; "but I have an idea that the devil and Strong may have something in common." "You don't think it was Strong who came and took the box, do you?" queried Adrian. "I don't know just what I do think, Ad; but I'm going to do a little detective work and I want to give the impression that we are all out. When you fellows go out, don't say anything that would cause any one in hiding to think we are not all going out together. Do you sabe?" "Sure. I hope you'll get a clue if we do not." When the others had gone, Billie sat quietly in his room for a long time. He could easily have gone to sleep, as he had had only a couple of hours' rest, but he made up his mind that he would not be caught napping again if anything should happen. But nothing happened. The minutes passed into hours and it was rapidly nearing noon when Billie made up his mind that it was a bad job. "We had our chance at daylight," he muttered, "and now we will not get another. Whoever is after the box, has it and is not going to take any further chance of being caught." He went out into the patio and looked up at the sun. It was almost in the zenith and the air was stifling. "Any one would be a fool to go out at this time of day," he mused. "I wonder where the fellows are?" He stepped back under the shade of the arcade that extended clear around the patio and threw himself onto a stone seat. "Queer old place," he thought, "and a queer old seat." He laid his hand on one of the carved arms and mechanically toyed with an eagle's head that formed one of the decorations. To his surprise the head turned in his hand. "I hope I haven't broken it," he said as he examined it more closely. It was clearly made to revolve and so he turned it clear around, when of a sudden the arm of the seat fell apart and the bottom collapsed, disclosing to Billie's astonished eyes a pair of stairs. Almost thrown to the pavement by the giving way of the seat, Billie picked himself up and looked about to see if he were observed.