“I would be willing to stake my life on it. I am so sure in the matter because one night not long since I wanted to do a little writing at his direction, and asked him if he had a steel pen, as I could not make out very well with his quills.” “He said he did not have any?” “Precisely. He said further that he had not had one in his possession in over ten years.” The detective then quietly said: “That puts me in possession of a good point.” “How so?” “I am not prepared to say just now. As to this young lady, you appear to know her?” “I do.” “You know where she lives so that she may be found in case she is wanted at any time?” “I do.” “That is well.” Barnes hesitated a minute, and then said: “Might it not be as well for you also to know her future address?” “It would do no harm.” “Then it will be here!” The detective turned quietly, and softly ejaculated: “Ah!” “Certainly. In the face of such evidence as this letter of Mr. Field’s she must remain here. I will attend to it and see that she is introduced to the servants as their new mistress.” “Well, as you please about that,” returned Nick, “it is none of my business.” The girl interposed: “Mr. Barnes, I do not wish to remain here. The money is nothing to me; I have so long taken care of myself that I should be positively unhappy, I believe, if I should make the attempt of playing lady.” “But you have a duty in the matter. You must remain here and occupy the position to which you are entitled.” “I will think of it.” “Think of it? Good heavens, does it require a minute’s reflection to settle the matter in your mind?” “It does.” “I will not listen to your going away from here now.” The girl said: “Mr. Barnes, I would take your advice in preference to that of anybody else, but I cannot fail to see that, no matter how strong the evidence, in the absence of a living recognition by Mr. Field, I should be thought to be an impostor.” “Nonsense! That letter is as good proof as human being could ask for.” And then, turning to the detective, he asked: “Doesn’t that letter settle the matter?” For reply, the detective simply said: “Yes.” Mentally, he added: “Yes, it does settle the matter, although not in the way that Barnes thinks it does. I must make some excuse for retaining possession of this forged letter.” CHAPTER XIX. PROVING THE LETTER. Satisfied that the urging of Barnes would result in Miss Doane’s remaining in the house, the detective went upstairs and into the library. The two left behind were too much engrossed to remember that the detective had possession of the letter. Arrived in the library he at once went to the desk and opening it, began to look around. He first took out the ink bottle and carried it to the better light near the window. It was a jet-black ink of heavy consistency, showing that a considerable quantity of gum arabic had been used in its manufacture.