And here again Wilfrid was met by a perplexing thought. Why should the Princess, presumably a member of the Court circle, choose the occasion of a public masquerade for presenting a letter which, one would think, might have been more suitably presented in private? And that letter, so she had averred, contained something of vital interest, not only to her own welfare, but also to Wilfrid’s. It was strange—passing strange—but then so was everything else happening that night. Wilfrid had never known a more mystifying time. When the hand of the clock was upon the stroke of two he repaired to the Hall of Mirrors, and, ascending a gallery, looked down upon the crowd of masked revellers. He hoped in a minute or two more to obtain a view of the Czar, and what was of more interest to him, of the Czarina, in case the Princess should be by to present her letter. But at the general unmasking, when everybody was looking expectantly around for the imperial pair, Prince Sumaroff mounted the dais and gave out that the pressure of State affairs had prevented the Czar from honouring the masquerade with his presence; a slight touch of illness had likewise kept the Czarina from attending. Wilfrid was, perhaps, the only one present that did not hear this disappointing announcement, his attention at that moment being absorbed by a fact of no importance whatever to the thousand and one guests, but constituting for him a startling discovery. A moment before the unmasking he had caught sight of Pauline, recognisable, of course, by her costume. She was leaning upon the arm of a tall and majestic figure clad in the glittering mail of a Byzantine warrior. Earlier in the evening when first entering the ballroom Wilfrid had noticed the man, and had called Pauline’s attention to his splendid and striking costume. The lifting of his mask gave Wilfrid a sort of shock. The Byzantine warrior was none other than Prince Ouvaroff! Clearly, then, unless Ouvaroff had changed his costume—a most unlikely event—he could not have been the Crusading knight whom Wilfrid had met upon the terrace. What man was it, then, with whom he had to fight at eight in the morning? CHAPTER XXI “YOUR OPPONENT IS AN EMPEROR” The unmasking of the guests was followed by a simultaneous movement toward the supper-tables, set forth in an adjoining room, a room scarcely inferior in size and grandeur to the Hall of Mirrors. Tormented by the thought of the Princess, Wilfrid was in no trim for eating, even when the far-famed Sumaroff _cuisine_ offered its temptations. Having satisfied himself that neither Marie nor the Crusading knight was among the guests, he withdrew from the palace, having first sent to Pauline a servant with a brief note, in which, without stating the cause, he expressed regret at finding it impossible to escort her home.