“It was a letter of mine, Mr. Holmes, an indiscreet letter written before my marriage⁠—a foolish letter, a letter of an impulsive, loving girl. I meant no harm, and yet he would have thought it criminal. Had he read that letter his confidence would have been forever destroyed. It is years since I wrote it. I had thought that the whole matter was forgotten. Then at last I heard from this man, Lucas, that it had passed into his hands, and that he would lay it before my husband. I implored his mercy. He said that he would return my letter if I would bring him a certain document which he described in my husband’s despatch-box. He had some spy in the office who had told him of its existence. He assured me that no harm could come to my husband. Put yourself in my position, Mr. Holmes! What was I to do?”

“Take your husband into your confidence.”