By the time their explorations were finished, Johnny declared that he was so hungry, he could almost eat one of those goose pies. The morning was quite gone. It would soon be time to take the train for Lucerne, and they must have dinner. "Won't Froll be glad to see us back!" exclaimed Johnny, as they reached their room; "she doesn't like to be left alone." Eric had bought some nuts for the little creature, and went with them straightway to her cage. The cage was just as he left it; the silver chain was there, too, fastened to one of the bars and to the tiny collar; but the collar hung dangling at the end of the chain, and Froll was nowhere to be seen. CHAPTER XI. ERIC IN TROUBLE. A thorough search was instantly made; but neither around the room, nor behind the furniture, nor upon the gallery roof, were any traces to be found of the lost Frolic. "It is too bad," cried Eric, in perplexity, while Johnny looked ready to cry. "We must speak to the landlord, and ask him what we are to do." Eric's German was by no means perfect; but he managed to make the good-natured landlord understand their trouble. He made inquiries of all, directly; but no one had seen the little monkey since the boys had left her. He did not think it at all likely that she had been stolen, for no one could get to the boys' room without being noticed by some of the servants, and he was quite sure that she would return safely to her comfortable quarters; so he advised the boys to leave the window open for her, and to go at once to the dinner he had been for some time keeping for them. His sensible advice was unwillingly followed; but Froll took no advantage of the window left open for her benefit. Eric and Johnny waited and watched impatiently, until it was almost time to start for the train. Then Eric left directions with the landlord, in case the monkey should be found and captured; promising to send for her. He was just going to call Johnny, when he heard his voice, crying, excitedly, "Eric, Eric!" and hoping Froll had returned, ran quickly up the stairs. "See there, what I found on the floor," exclaimed Johnny, as he entered the room, and held up before Eric's astonished gaze a jewelled ring, that flashed and sparkled in the sunlight. "Good gracious!" exclaimed Eric; "on the floor of _this_ room?" "Yes," answered Johnny, "on the floor, just where you're standing. It's a mercy we haven't stepped on it. Don't you think so?" "We must find the owner at once. Isn't it splendid!" said Eric, admiringly; "three diamonds and an emerald; it must have cost a fortune." Just at this juncture the door opened, and the landlord, followed by a French officer and a civilian, entered the room. The landlord exclaimed, in German,-- "I beg your pardon, young gentlemen, but a serious loss has occurred in the house, and as you are about leaving it, perhaps you will be kind enough to let us inspect--"