Shortly after lunch, then, on this day, the eighth after the burglary and drugging, Cheyne, on re-entering the house after a stroll round the garden, was handed a card and told that the owner was waiting to see him in his study. Mr. Arthur Lamson, of 17 Acacia Terrace, Bland Road, Devonport, proved to be a youngish man of middle height and build, with the ruggedly chiselled features usually termed hard-bitten, a thick black toothbrush mustache, and glasses. Cheyne was not particularly prepossessed by his appearance, but he spoke in an educated way and had the easy polish of a man of the world. “I have to apologize for this intrusion, Mr. Cheyne,” he began in a pleasant tone, “but the fact is I wondered whether I could interest you in a small invention of mine. I got your name from Messrs. Holt & Stavenage, the Plymouth ship chandlers. They told me you dealt with them and how keen you were on yachting, and as my invention relates to the navigation of coasting craft, I hoped you might allow me to show it to you.” Cheyne, who had had some experience of inventors during six weeks’ special naval war service after his convalescence, made a noncommittal reply. “I may tell you at once, sir,” Mr. Lamson went on, “that I am looking for a keen amateur who would be willing to allow me to fit the device to his boat, and who would be sufficiently interested to test it under all kinds of varying conditions. You see, though the thing works all right on a motor launch I have borrowed, I have exhausted my leave from my business, and am therefore unable to give it a sufficiently lengthy and varying test to find out whether it will work continuously under ordinary everyday sea-going conditions. If it proves satisfactory I believe it would sell, and if so I should of course be willing to take into partnership to a certain extent anyone who had helped me to develop it.” In spite of himself Cheyne was impressed. This man was different from those with whom he had hitherto come in contact. He was not asking for money, or at least he hadn’t so far. “Have you patented the device?” he asked, reckoning willingness to spend money on patent fees a test of good faith. “No, not yet,” the visitor answered. “I have taken out provisional protection, which will cover the thing for four months more. If it promises well after a couple of months’ test it will be time enough to apply for the full patent.” Cheyne nodded. This was a reasonable and proper course. “What is the nature of the device?” he asked. The young man’s manner grew more alert. He leaned forward in his chair and spoke eagerly. Cheyne frowned involuntarily as he recognized the symptoms.