"I should like to know the meaning of this," Rigby whispered. "I suppose it refers in some way to the mysterious music which you told me about last night. Do you think it possible that Serena could enlighten us on this point as she appears to know all about it? If not, why does she look at Padini in that scornful way?"

Any further signs of enjoyment on the part of Padini were cut short by an impatient oath from Anstruther.

"That is mere child's play," he exclaimed. "Very clever and all that kind of thing, but an intelligent schoolboy might have done as well."

Jack intimated in a whisper to Rigby that he himself stood in the position of the said intelligent schoolboy. He had a pretty shrewd idea how the thing had been managed, and to what purpose; but there would be time enough to explain all that presently. What they had to do now was to stay as long as possible, and gather all they could from a careful study of the proceedings taking place in the room. It was Anstruther who first broke the silence.

"Are we going to stand fooling here all night?" he exclaimed angrily. "Padini, get that exaggerated fur coat of yours off, and make yourself up to look like an English gentleman as far as possible. You will find everything necessary in the room at the back of the house. The same remark applies to you, Serena. My word! To think that a woman so pale, so haggard, as you are now can make up to look like eighteen and possess the beauty of Diana! What a pity it was you ever left the stage!"

The woman's face flushed angrily. There was a nervous tension about her to-night that Anstruther had never noticed before. Was she going to be defiant? he asked. Did she understand what she was doing when she proposed to measure her strength against his? But the flame still raged on Serena's hot cheeks, and her lips were still hard and mutinous.

"Take care you do not drive me too far," she whispered hoarsely. "A cat is a harmless creature enough, but I read once of a cat that turned upon a man and killed him. You dare to taunt me with my past. When I think of what that past might have been but for you, I declare that I could find it in my heart to kill you. I am so weak and timid, you are so strong and brave; and yet even you must sleep at times, and a man asleep is as harmless as a babe. A spot of gray powder, a drop of liquid no larger than a pin's point placed between your teeth, and the career of Spencer Anstruther is finished."

The words were uttered with such dramatic force and intensity that even Anstruther refrained from smiling. It seemed to the listeners outside that here was a great genius lost to the stage.

"I should not care to encounter that woman's hostility," Rigby murmured. "Look at the intense expression of her face. But, really, I hope she is not going to defy him to-night. If she does we are likely to have trouble for our pains."

But Serena's outbreak of passionate anger was over as swiftly as an April shower. She looked up in the face of her master as a dog might do that had been convicted of theft. Anstruther smiled with the air of a man who merely tolerates a passing anger of a fellow creature. It was as if he had caged this woman so that he could watch her passions and emotions as a naturalist studies the habits and ways of loathsome insects.