Not that he failed to trust Mary Sartoris. In spite of everything, he had faith in her. Whatever she was doing in that queer household, no shadow of shame or disgrace could possibly lie on her. And yet what could she want that letter for? Again, what was the need to drag Beatrice Darryll into this black business? The more Berrington thought it over, the more puzzled he became. Only one thing was tolerably clear--Sir Charles Darryll had valuable interests somewhere, interests of which he had been in utter ignorance, and which these ruffians had determined to obtain and apply to their own ends. Still, Berrington hesitated. He did not know what would be for the best. If he declined to write that letter it might be the worse for him and everybody else in the long run; if he did write the letter it might possibly prove harmful to Beatrice. Certainly Carl Sartoris had that end in view. Then there was another thing to take into consideration. Had Inspector Field got safely away? Berrington could not be absolutely certain, for the reason that there had been no attempt to rescue him which was Field's obvious duty when he escaped. Yet a great many hours had passed and there had been no attempt of the kind. Very thoughtfully Berrington took paper and pen and ink from the drawer in the table. He was not surprised to see that the paper bore the address "100, Audley Place." So Beatrice was to be lured there for some reason, or other, and Berrington was to be used for the purpose. He threw the pen down and determined that he would do nothing in the matter. He had barely come to this conclusion when the whistle in the tube sounded very faintly. It might have been no more than the wind in the pipe, and yet on the other hand it might have been meant for a cautious message. Berrington crossed over and asked a question in a low voice. Immediately a reply came in the faintest possible whisper. "It is I who speak," the voice said. "Mary, you know. By accident I have a chance of a few words with you again. My brother thinks that I am in ignorance of everything. He told me that you had left the house and that everybody had gone. At the same time he declined to have the servants back yet, and that aroused my suspicions. You can hear me?" "My dearest girl, I can hear you perfectly well," Berrington replied. "Where is your brother now? Can you speak freely to me for a time?" "For a minute or two perhaps, certainly not more. Carl has gone into the conservatory for something; he may be back almost at once. He told me that you had gone. I did not believe it for a minute, so I watched and listened. Then I found out that you were a prisoner here; I found out all about the letter." "The letter to Beatrice Darryll, you mean?"