As Sebastiana had predicted, there was a considerable sprinkling of dominoes amongst the motley throng; and as usual, of those who had selected that dress, more favourable to concealment and intrigue than to display of personal graces or costly ornaments, at least one-half had preferred black to any other colour. These latter seemed the subject of the particular attention of one of their number, who, soon after twelve o'clock, made his appearance in the ball-room. Impatience to share in the much-talked-of fête had rendered the invited punctual; by that hour nearly all had arrived, and in such numbers that the rooms, though so large and numerous, were crowded at least as much as was convenient and consistent with circulation. Hence the black domino was frequently impeded in the rapid movements he commenced whenever one of his own species--that is to say, a domino of the same colour--caught his eye, movements which had for their object to meet or overtake the person of garb similar to his own. On such occasions, so great was his impatience, that in a public ball-room he would surely have incurred a quarrel by the somewhat too vigorous use he made of his elbows. But Madame de M----'s well-bred guests merely shrugged their shoulders, and wondered who the _manant_ could be who thus imported into their élite society the unceremonious usages of an opera-house masquerade. The black domino heeded not their mute wonderment, nor cared for the unfavourable impression he might leave upon the ribs and the minds of those he jostled. He was evidently looking for somebody, and however discouraging the task of seeking one particular black domino in a crowded masquerade, where there were two or three score of them, he persevered, in spite of repeated disappointments. At last it seemed as if success had rewarded his constancy. With the suddenness and certainty of a well-broken pointer, he came to a dead stop at sight of a black satin domino leaning on the arm of an elegant Hungarian hussar. To the steps of this couple he thenceforward attached himself. Whithersoever they went he followed, keeping at sufficient distance to prevent their noticing his pursuit; regulating his pace by theirs, but occasionally accelerating it so as to pass them, and lingering for a second when close at their side, as if trying to distinguish the tones of their voices, or to catch a few words of their discourse. Whilst thus engaged, he did not observe that he had himself become an object of attention to a third black domino, who, previously to him, had been dogging, but at greater distance, and with still more precaution than he observed, the steps of the hussar and his companion. The curiosity and caution of domino No. 3 appeared to receive fresh stimulus from the apparition of a rival observer, over whose movements he kept careful watch, but from afar, and concealed as much as possible amongst the crowd, somewhat after the fashion in which the Red