"Well, there is," I confessed. "You remember a chap called Dr. Manning--the fellow who looked after my uncle when he was dying?" Once again the Inspector nodded. "Yes," he answered. "I remember him very distinctly. He lived on a barge about three hundred yards above the island." "That's the gentleman," I said. "He's living there still; in fact, to all intents and purposes he's my next-door neighbour. What I want you to do, if you can possibly spare the time, is to get me a little accurate information about his past life." If my companion felt any surprise or curiosity he certainly didn't show it. "That oughtn't to be very difficult," was his reply. "Doctors are fairly easy to trace as a rule." He reached across to the table and picked up a half sheet of notepaper. "Has he ever mentioned a particular town, or given you any idea of what hospital he was at?" "He once told me he had been a ship's surgeon," I said. "It was probably a lie, so I shouldn't attach much importance to it." The Inspector made a brief note. "One never knows," he observed hopefully. "People sometimes tell the truth by accident. They generally regret it afterwards." A telephone bell tinkled sharply in the corner of the room, and with a word of excuse he rose from his seat and walked across to the instrument. "Yes," he said. "I'm Campbell--speaking." There was a pause. "What's that?" Another and longer pause followed. "Oh, very well. Don't let him go. I'll be round almost immediately." He hung up the receiver and turned back to me. "I'm sorry," he said, "but I'm afraid I shall have to run away after all. I have got to meet a man who wants to leave for Scotland this afternoon." He folded up the paper he was holding, and put it away carefully in his pocket "I'll get on to this little job at once. You shall hear from me directly there's any news." "Thanks," I said gratefully; "and, meanwhile, if the wicked should happen to cease from troubling----" "You'll not only hear from me, but see me." He gave me a friendly grip, and, collecting his hat and stick, led the way out into the yard. We walked together under the archway and emerged on to the crowded pavement of Fleet Street. "There's one thing I should like to add, Mr. Dryden," he said, just before we parted. "If you ever find yourself in real difficulty or actual danger, don't hesitate to let me know. Whatever I'm doing I shan't be too busy to lend you a hand." I tried to thank him, but, without waiting to listen, he stepped off into the roadway, and a moment later he was swallowed up amongst the traffic.