The young man had an eye for colour, but knew very little about millinery, so if anyone later had asked him to describe the various dresses, he would have been puzzled. But one woman wore a dress which attracted him from its oddity. It was a flowing gown of white silk, and from hem to waist the skirt was adorned with triple lines, at intervals, of narrow red velvet. The spaces between the triple lines were equal, and the lines of red velvet themselves ran apparently entirely round the skirt. The effect was bizarre, and rather fascinating; but what made Prelice note the dress so exactly was the wonderful ubiquity of the lady who wore it. He went into the ballroom of the right-hand flat, and there she was dancing; he strolled into the left-hand ballroom, and found her flirting in a corner with another partner. Then he stumbled across her in the corridor, and later discovered her at the buffet sipping champagne. Her domino was green, as was her mask, and she seemed to be in several places at once. Prelice was amused at her activity, and at the way in which she seemed to permeate the entire place. She was certainly getting all the enjoyment she could out of the ball. He spoke to her once, but she made no reply, and disappeared before he could address her again. Rather annoyed that she would not respond, Prelice yawned, and discovering that it was half-past-eleven, decided to descend and look up Shepworth. The stairs were crowded, not only with people leaving and arriving, but with flirting couples, who were cooling themselves in the purer air, which ascended from the main entrance of the mansions. These expostulated loudly, and sometimes silently--if irritated gestures went for anything--with those who pushed past them to go up or down. Prelice came in for his share of blame, as he cautiously steered his way to the second floor. Here there were but few people, as the guests kept to the third-floor stairs and to those leading to the fourth. A look at the left-hand door as he came down showed Prelice that it was Number Forty, so he pressed the button of the electric bell, and waited for the door to be opened. As he did so, and while he was leaning against the wall, still wearing his mask and domino, the ubiquitous lady in the green domino with the oddly trimmed frock descended the stairs alone. She cast a swift look at him as he passed, and it was not until she vanished below that Prelice became aware that the scent of the tuberose was again in his nostrils. He had half a mind to run after her, and--assuming the privilege of a masked ball--ask her if she was wearing such a flower. But, in his idle way, he did not think it was worth while, and remained where he was.