I confess that when it came my turn to watch them I became more than ever convinced that Raymond's suspicions were ungrounded. They seldom went out, and when they did, it was either to dine with Hartmann, or to stroll about the suburban roads of Norwood, Sydenham, and Penge.
Late one afternoon, however, while I was down at Sydenham, I saw them emerge from the house, carrying their small suit-cases, and followed them to King's Cross Station, where they took tickets for Hull.
Instantly I rushed to the telephone and informed Ray in Bruton Street of my intention to follow them.
That same night I found myself in the smoke-grimed Station Hotel in Hull, where the two foreigners had also put up.
Next day they called at a solicitor's office at the end of Whitefriargate, and thence, accompanied by a man who was apparently the lawyer's managing clerk, they went in a cab along the Docks, where, at a spot close to the Queen's Dock, they pulled up before an empty factory, a place which was not very large, but which possessed a very high chimney.
The managing clerk entered the premises with a key, and for about half an hour the pair were within, apparently inspecting everything.
I was puzzled. Why they were in treaty to rent a place of this description was an utter enigma.
They returned to the hotel to luncheon, and I watched them engaged in animated discussion afterwards, and I also noticed that they despatched a telegram.
Next day they called upon the solicitor, and by their satisfied manner when they came forth from the office, I guessed that they had become tenants of the place.
In this I was not mistaken, for that same afternoon they went together to the factory and let themselves in with the key, remaining within for over an hour, evidently planning something.