Acting upon the advice of Nick Carter, she went into Hertfordshire, England, determined to make peace, if possible, with certain relatives who still lived there. And Nick Carter returned at once to New York. CHAPTER XXII. A SECRET MISSION. It was not long after the detective’s return from abroad that Joseph, his major domo, ushered a stranger into the library, bowed to him, and said: “Mr. Carter is engaged for the moment, sir, but he will be at liberty presently. I will tell him that you have arrived.” The stranger nodded his head and stood like a wooden image until Joseph had left the room. Then his tall and soldierly figure relapsed upon a chair, and he stared across the room at nothing during the entire interval of waiting. Above stairs in the study when Joseph presented himself there, with the card of the stranger, Nick Carter received it, glanced at it, nodded to Joseph, who passed from the room again, then turned to Chick, who was near the window, and said: “Go down to the library, Chick. Look the fellow over for me. Tell him that I’ll be down presently. Then come back here and tell me what you think of him.” Chick left the study in obedience to this direction, and the moment he was gone the detective picked up an opened letter that was on the desk in front of him and read it once more, from beginning to end. It was typewritten, on a letter head of the Russian embassy, in Washington, and after the usual superscription, it said: “I hope you will regard this letter in the light of a personal matter, not intended to be at all official in its character. When it is possible to enjoy a personal interview with you, I will explain fully that point, and all the others that are connected with this affair. I have not had the honor to make your acquaintance, but I need only say to you that it is a mutual friend of ours who has induced me to make a demand upon your services, and that I do so acting solely upon his advice. “And of your services in a matter of extreme delicacy, I stand greatly in need, so I beg that you will come to Washington—since it is utterly impossible as well as impolitic for me to go to you—as soon as you can make it convenient to do so. The direct purpose of this letter is to prepare you for the reception of a gentleman of my staff whom I have sent to you with credentials, and who will explain, in part, the dilemma in which I have unfortunately become involved. Please understand that I make no charge against the gentleman mentioned, but his position and his relations with me and with my household have been such that I would be glad if you take this opportunity of studying him somewhat. “I have the honor to remain, my dear sir, “Your most obedient and humble”—etc., etc., etc.