Nick had heard of such cases. He did not reply to the grief-stricken girl, nor make any comments. He took a letter which she, starting up while speaking, hurriedly brought from the library table and tendered with trembling hand. It was a typewritten letter, on paper bearing the printed business heading of the missing banker, also the date of the previous day. It read as follows: “My Dear Mina: I am writing you a few lines before leaving my office, on a subject which, though I am to see you within an hour, I have not the heart or courage to discuss with you in person. “This is a late day, indeed, for me to discover that it is best for us to part permanently; that I would do you a far greater wrong in making you my wife, than in taking the step I am about to take. Conditions have arisen that make it imperative, however, and I can see no wise, or even possible, alternative. I shall be far away when you read this, and it is my intention never to return. I cannot ask you to forgive me. My only hope is that you can forget me, and in time find one more worthy of you. “You already have the deed of the new place, which, with all it contains, I hope you will keep in part amendment of the wrong I have done you. Do please try to forget me. ARTHUR GORDON.” Nick Carter’s grave, clean-cut face, on which Mina Strickland’s tearful blue eyes were anxiously riveted, underwent no change while he read the letter. He handed it to Patsy Garvan, his junior assistant, who had accompanied him there, saying quietly: “Read it, Patsy. The case evidently is one that we must investigate.” Patsy obeyed, without replying. “Please tell me at once, Mr. Carter,” Mina pleaded. “Do you think that----” “That Arthur Gordon wrote it?” Nick interposed, turning to her. “Yes.” “Frankly, Miss Strickland, I do not.” “Oh, thank Heaven for that!” cried the girl. “Your opinion is worth more to me than that of all the world. It must be, then, that he is the victim of----” “Stop a moment,” Nick again interrupted. “My opinion will be worth more after I know all of the circumstances. It now is based only upon the fact that all this is very unlike Arthur Gordon.” “It is, indeed.” “Let me question you. That will be the quickest way to bring out the salient points,” said Nick. “Answer as briefly as possible. You received the letter this morning?” “Yes, sir,” said Mina, eager to proceed. “The written signature is like Gordon’s?” “Precisely.” “You have had other letters from him, of course?” “Yes, many, Mr. Carter.” “Were they usually typewritten?” “No, no, very rarely. He nearly always used a pen.” “Do you know whether he can use a typewriter skillfully, or even easily?” “I don’t think so,” said Mina. “I think he dictates all of his typewritten letters.”