The curtain was rising upon the first act of the ballet as they entered the music-hall and were shown to the box which Peter had engaged. The house was full--crowded, in fact, almost to excess. They had scarcely taken their seats when a roar of applause announced the coming of Mademoiselle Louise. She stood for a moment to receive her nightly ovation, a slim, beautiful creature, looking out upon the great house with that faint, bewitching smile at the corners of her lips which every photographer in Europe had striven to reproduce. Then she moved away to the music, an exquisite figure, the personification of all that was alluring in her sex. Violet leaned forward to watch her movements as she plunged into the first dance. Peter was occupied looking round the house. Monsieur Guillot was there, sitting insolently forward in his box, sleek and immaculate. He even waved his hand and bowed as he met Peter's eye. Somehow or other, his confidence had its effect. Peter began to feel vaguely troubled. After all, his plans were built upon a surmise. It was so easy for him to be wrong. No man would show his hand so openly who was not sure of the game. Then his face cleared a little. In the adjoining box to Guillot's the figure of a solitary man was just visible, a man who had leaned over to applaud Louise, but who was now sitting back in the shadows. Peter recognised him at once, notwithstanding the obscurity. This was so much to the good, at any rate. He took up his hat. "For a quarter of an hour you will excuse me, Violet," he said. "Watch Guillot. If he leaves his place, knock at the door of your box, and one of my men, who is outside, will come to you at once. He will know where to find me." Peter hurried away, pausing for a moment in the promenade to scribble a line or two at the back of one of his own cards. Presently he knocked at the door of the box adjoining Guillot's and was instantly admitted. Violet continued her watch. She remained alone until the curtain fell upon the first act of the ballet. A few minutes later Peter returned. She knew at once that things were going well. He sank into a chair by her side. "I have messages every five minutes," he whispered in her ear, "and I am venturing upon a bold stroke. There is still something about the affair, though, which I cannot understand. You are absolutely sure that Guillot has not moved?" Violet pointed with her programme across the house. "There he sits," she remarked. "He left his chair as the curtain went down, but he could scarcely have gone out of the box, for he was back within ten seconds."