"Your affectionate cousin, "HENRY LEWIS." That letter, innocent enough upon the face of it, contained certain instructions to the spy, besides enclosing his monthly payment of £20. Read by the alphabetical instructions with which every German secret agent is supplied and which vary in various districts, the message it contained was as follows: (Phrase I) I send you your monthly payment. (Phrase 2) Your informations during the past month are satisfactory. (Phrase 3) Your service in general is giving satisfaction, and if it continues so, we shall at the next inspection augment your monthly payment. (Phrase 4) We wish you, however, to send us more detailed notes, and report oftener. (Phrase 5) Cease your observations upon Charles. We have what we require. Turn your attention to defences at Tynemouth. (Phrase 6) As you know, the chief (spring) is very difficult to please, for at the last inspection we were given increased work. (Phrase 7) Remain in negotiation with your three correspondents--Charles (meaning the foreman, Rosser), Charlotte, and Frederick--until you hear further. You may make them offers for the information. Thus it will be seen that any one into whose hands this letter from "Henry Lewis" fell would be unable to ascertain its real meaning. The fictitious Lewis, we afterwards discovered, occupied a small office in Berkeley Chambers in the guise of a commission agent, but was no doubt the travelling agent whose actions were controllable by Hermann Hartmann, but who in turn controlled the fixed agents of that district lying between the Humber and the Tweed. Most of these travelling agents visit their fixed agents--the men who do the real work of espionage--in the guise of a commercial traveller if the agent is a shopkeeper, or if he is not, he will represent himself as a client or an insurance agent, an auctioneer or a house agent. This last _métier_ is greatly recommended by the German Secret Police as the best mode of concealing espionage, and is adopted by the most dangerous and ingenious of the spies. When I returned I showed my treasures to Ray, who at once became excited. "The fellow is a fixed agent here in Newcastle, no doubt," he declared. "We must watch him well." We continued our observations. The spy and Rosser were inseparable. They met each evening, and more than once the whole Rosser family went out to entertainments at Mr. Barker's expense. He would allow the foreman fitter to pay for nothing. Judicious inquiries at Elswick revealed the fact that Charles Rosser was one of the most skilful fitters in the employ of the firm, and that such was the confidence placed in him, that he was at present engaged in the finishing of the new gun which was to be a triumph of the British Navy--a weapon which was far and away in advance of any possessed by any other nation, or anything ever turned out from Krupp's.