"Yes," said Flossy placidly, "I have tried it before." She took a little bottle of greenish glass from the small morocco bag which she carried in her hand, and held it up to the light. "There are two doses in it," she said. "Don't use it all at once. A drop or two more or less does not matter; you need not be afraid of making it a little too strong. It is colorless and tasteless. Can you manage it?" Sabina considered. "If I put it into the tea-pot, it might be wasted; he might not drink all the tea. He never lets me pour it out for him. Would it alter the look of the milk?" "Not at all." "Then I could put it into his cream-jug, and give him so little that he's sure to use it all and ring for more. He likes a deal of milk in his tea." "Then you will do it, Sabina?" Again Sabina hesitated. Finally she said, with sudden decision-- "Give me that twenty pound, and then I will." "Not until you have earned it." "If I don't have it beforehand, I won't do it at all," said Sabina doggedly. Mrs. Vane shrugged her shoulders slightly, opened her bag, and put the little bottle back into its place. "You said you could trust me; show me that you can," said Sabina, unmoved by this pantomime. "One of us will have to trust the other. I may do it, and then--who knows?--you may back out of the bargain." "Did I ever 'back out of a bargain,' as you coarsely express it? I think, Sabina, I have trusted you a good deal already." "Well, split the difference," said Sabina roughly. "Give me ten down on the nail, and ten when I've done the work. I dare say I can manage it to-night. I can write to you when it's over." "Very well. Here are ten pounds for you; I will give you the other when your work is done. But do not write to me; come to me at the Grosvenor Hotel to-morrow morning. I shall stay the night in town!" "Have you any idea who the man is?" said Sabina, as she received the bottle and the ten-pound note from her visitor's hands. "Yes, I have; but I may be wrong." "That's not very likely, ma'am. You'd 'a' made a good detective, as I always did think--you're so sharp." "And I don't look it, as you said before. Perhaps I will tell you to-morrow morning, Sabina. At present I am going to find out all that I can about Miss Cynthia West. You did not give me her address; give it to me now." She wrote it down in a little pocket-book, and then rose to take her leave. Sabina, who followed her to the cab, heard her tell the man to drive to the box-office of the Frivolity Theatre.