After nearly three weeks in London, Dubois and Gessner returned to Hull, where, while living at the Station Hotel, they spent each day at their "works." They engaged no assistant, and were bent apparently upon doing everything by themselves. They were joined one day by a shrivelled-up old man of rather seedy appearance, and typically German. His name was Busch, and he lived in lodgings out on the Beverley Road. He was taken to the works, and remained there all day. A quantity of electrical appliances were delivered from London, and Dubois and Gessner received them and unpacked them themselves. Ray Raymond was down at Sheerness upon another matter--a serious attempt to obtain some confidential naval information--therefore I remained in Hull anxiously watching. Vera had again offered her services, but at that moment she was down at Sheerness with Ray. Day by day old Busch went regularly to the factory, and by the appearance of the trio when they came forth, it was apparent that they worked very hard. I was intensely inquisitive, and dearly wished to obtain a glance within the place. But that was quite out of the question. Busch, it seemed, had lived in Hull for a considerable period. Inquiries of his neighbours revealed that he was a well-known figure. He did but little work, preferring to take long walks into the country. One man told me that he had met him twice away near Spurn Head, at the estuary of the Humber, and on another occasion he had seen him wandering aimlessly along the low-lying coast in the vicinity of Hornsea. In explanation of this, it seemed that he had once lived for a whole summer in Withernsea, not far from Spurn Head, and had grown fond of the neighbourhood. Everybody looked upon him as a harmless old man, a trifle eccentric, and a great walker. That constant rambling over that low-lying district of Holderness had aroused my suspicions, and I determined to turn my attention to him. One day the old man did not go to the factory, but instead went forth upon one of his rambles. He took train from Hull to Hornsea, where the railway ends at the sea, and walked along the shore for several miles; indeed until he was three parts of the distance to Bridlington, when he suddenly halted near the little village of Barmston, and producing a neat pocket-camera took a long series of snap-shots of the flat coast, where I saw there were several places which would afford an easy landing for the invader.