"Do you like Colonel Ilse?" asked Miss Toat when the door closed. "Very much," said Audrey, frankly. "He seems to be a very nice man, but sad." "Ah! it is my task to turn his sadness into joy," said the detective, looking keenly at her client. "By finding his daughter?" "Yes, by finding his daughter," assented Perry Toat, who looked a sharp little rat of a woman as she sat at the table. "And now, let us come to your business, Miss Branwin. I can't give you much time, so please state what you wish to see me about as speedily as possible." "I speak in confidence, of course," hesitated Audrey, rather embarrassed. "Of course, in strictest confidence. What is it?" "It is about Mr. Shawe. I can't understand him." "But you are engaged to marry him." "Yes." Audrey flushed. "And I love him very dearly. I don't mind telling you this, as you are a woman and can understand. But lately there is something queer about him. I wish him to learn who murdered my mother, and he has been trying. But over a week ago he asked me to give up the search." "Oh"--Perry Toat sat up alertly--"he asked you to give up the search. Why?" Miss Branwin felt in her pocket and brought out the anonymous letter. "For this reason," she said, passing it to Perry Toat. "This letter warns me that if I persist in searching into the case I shall experience the greatest grief of my life." "Oh!" said Perry Toat again, and ran her sharp eyes over the ill-written lines. "And Mr. Shawe agrees with this letter?" "Yes. He is most anxious to get me to give up searching, and always avoids answering my questions as much as he can. To-day I had an appointment to see him in Kensington Gardens, but he did not appear. This is the first time he has ever behaved in this way, so I came at once to ask you if you can tell me the reason for his change of mind." Perry Toat looked hard at the anonymous letter, and did not answer. After a time she went to a tin box and brought out some papers, with which she compared the missive addressed to Audrey. "Let me look at the envelope, please," she said after a long pause. "Oh, here it is." She picked it up from the table and examined the postmark. "What do you make of it?" asked Audrey, impatiently. "Of this letter? Oh, it is written by someone who wants the case stopped." "By the assassin?" "Why do you think it might be the assassin?" "Because only the assassin would like an end put to the case." "Humph!" said Miss Toat, anxiously. "That is one view; but there is another, Miss Branwin. A certain person may be anxious to prevent your learning the truth in case it should cause you great pain." "So the letter says," said Audrey, quickly. "But I don't understand, unless--" Suddenly she stopped, with her mouth open. "Oh!" she gasped faintly, for it had just occurred to her what Mrs. Mellop had hinted, "you don't think that my father wrote it?" "No." Perry Toat looked astonished. "Why should you think your father--"