"The question of expense is frequently a puzzling matter with us, movements requiring an unauthorized expenditure of money sometimes occurring suddenly, when there is not time to consult our clients. If I had allowed Mr. Nisbet to leave the country unaccompanied he might have slipped through your fingers; in any event it would have been a great trouble, and have necessitated the expenditure of much more money, to pick up the broken threads. Many a good case has been spoiled by parsimony." "I understand that. Where has Mr. Nisbet gone to?" "I cannot inform you yet. As far as Paris, certainly; but my impression is he goes farther. My officer will telegraph me from Paris, and will not leave him till he has reached his destination." I considered a moment, and then took Bob aside. "Will you accompany me to Paris?" I asked. "With pleasure." I turned to Mr. Dickson. "Your officer will telegraph to you from Paris?" "Yes." "If I wait here for information I shall lose a day. You could telegraph to me in Paris the address you receive from your officer?" "There is no difficulty. You intend to follow?" "I do. Give me the name of some central hotel in Paris where I can put up till I receive your telegram." "Hôtel de Bade, Boulevard des Italiens." "That will do. I have something to do here in London before I can start. I can get through my business in about an hour, perhaps a few minutes more. Bob, run out and bring two hansoms with smart horses." Bob vanished. "Now, the best train, Mr. Dickson?" "Let me see. It is not yet nine. Your business say an hour and twenty minutes. A train from Victoria, another from Charing Cross, at eleven. Could you catch one of these, whichever is the nearest for you?" "Yes." "You arrive in Paris at seven this evening. Our man will reach there two hours and a half earlier. You may get a telegram from me at the Hôtel de Bade within an hour or so of your arrival." "Capital. Good-morning." The cabs were at the door, and I told Bob to drive with speed to my house, to pack up a bag for both of us expeditiously, and to meet me at Ronald Elsdale's house at a little after ten. The cab was to remain there, and he was to detain his nephew till I joined him there. Pending my arrival he was to tell Ronald everything. I gave him a line to my servant, authorizing him to take what clothes were necessary for the journey. "Double fare," I said to both the cabmen, "if you drive at your fullest speed." The next moment Bob was driving to my house and I was on my way to Dr. Cooper. CHAPTER XXIII. ON THE TRACK.