ouse in Hopton Road, Streatham Hill.

Fowler had become a frequent visitor at their house, while, on several
occasions, he dined with Dubois at De Keyser's Hotel, facing Blackfriars
Bridge.

In consequence of some conversation I one evening overheard--a
conversation in English, which the Belgian spoke fluently--I judged
Fowler to be an electrician, and it seemed, later on, very much as
though he had been, or was about to be, taken into partnership with
them.

As far as we could discover, however, he had been told nothing about the
factory in Hull. More than once I suspected that the two foreigners were
swindlers, who intended to "do" the Englishman out of his money. This
was impressed I upon me the more, because one evening a German woman was
introduced to their newly-found friend as Frau Gessner, who had just
arrived from Wiesbaden.

Whether she was really Gessner's wife I doubted. It was curious that, on
keeping observation that evening, I found that the lady did not reside
at Sydenham, but at a small hotel in Bloomsbury, not a stone's-throw
from my own rooms.

There was certainly some deep game in progress. What could it be?

Vera had watched Fowler on several occasions, but beyond the fact that
he was an electrical engineer, occupying a responsible position with a
well-known telegraph construction company, we could discover nothing.

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 t