When he had exhausted his memory, he said to himself that there must be some abstract reason for that sensation. It must be due to the fact that she was the ideal type of beauty of which he had always dreamed, but which he had never been able to grasp and produce. That was a poetic commonplace. He was fain to be content with it for lack of a better. But the princess was not alone, for she was talking; and Michel soon discovered that she was tête-à-tête with a man. That was certainly a reason to impel him to withdraw, but it was difficult to do so. To preserve the mysterious obscurity of the grotto and exclude the brilliant light of the ball-room, the entrance had been masked by a heavy blue velvet curtain, which our inquisitive hero, by the merest chance, had drawn aside a little way when he entered, without attracting the attention of the two persons who were talking there. The entrance to the grotto being only half as wide as the grotto itself, formed a frame, not of artificial rocks, as would have been the case with us, in our imitations of _rococo_, but of genuine blocks of lava, vitrified, and of divers shades of color, curious and valuable specimens collected long before in the very crater of the volcano to be set like jewels in the masonry. This beautiful door-frame protruded far enough into the grotto to conceal Michel, who was able to see because of its uneven surface. But, in order to go out, he must raise the curtain again, and he could hardly hope that both the princess and her companion would be sufficiently engrossed not to notice him. Michel thought of all this too late to avert the consequences of his imprudence. It was too late for him to go out naturally, as he had entered. Moreover he was nailed to his place by the most intense curiosity and anxiety. Doubtless that man was the princess's lover. He was a man of about thirty-five years, tall, and with a grave, sweet face, wonderfully handsome and regular. In his manner, as he sat facing Agatha at a distance, which indicated something betwixt respect and intimacy, there was nothing to criticise; but when Michel had recovered his presence of mind sufficiently to listen to the words that fell upon his ears, he fancied that he could detect an indication of mutual affection in this observation of the princess: "Thank heaven it has not yet occurred to anyone to raise the curtain and discover this delightful retreat; although I might naturally take some pride in bringing my guests here,--for it is beautifully decorated to-night,--I would like to pass the night here all alone, or with you, marquis, while the fête and the dancing and the tumult run their course behind the curtain." The marquis replied, in a tone which did not indicate a presumptuous man: