He remained there about half an hour, but whether he received any answering signal I know not.
Next night and the next I went to the same spot, but he failed to put in an appearance. Then, in order to report to Ray, I joined the morning train from Perth to London.
On arrival at New Stone Buildings I telephoned to Bruton Street, but Chapman, his valet, told me that his master had slept there only one night, had received a visit from a respectably dressed middle-aged woman, and had gone away—to an unknown destination. Therefore I waited for a whole week in anxiety and suspense, until one morning I received a wire from him, despatched from Kirkcaldy, urging me to join him at once at the Station Hotel in Perth.
Next morning at nine o'clock I was seated on the side of his bed, telling him of the incident of the lamp.
"Ah!" he exclaimed after a pause. "My surmises are slowly proving correct, Jack. You must buy a bicycle-lamp down in the town and a piece of green glass. To-night you must go there at the same hour and show a similar light. The matter seems far more serious than I first expected. The enemy is no doubt here, in our midst. Take this. It may be handy before long," and he took from his kit-bag a new .32 Colt revolver.
By this, I saw that he had resolved upon some bold stroke.
That evening, after an early dinner at the hotel, we took train to North Queensferry, and on alighting at the station he sent me up to the golf-links to show a light for half an hour; promising to meet me later at a certain point on the road to Rosyth.
I gained the lonely spot on the golf-course and duly showed the light. Then I hastened to rejoin my friend at the point he indicated, and found him awaiting me behind some bushes.
Almost at the moment we met, a female figure came along beneath the shadow of a high wall. She was a poorly dressed girl, but the instant she addressed my friend I recognised by her refined voice that it was Vera, the dainty daughter of the Admiral Superintendent.
"Elsie is waiting down by the Ferry Barns," she said quickly, in a low whisper, after greeting me. "Heinrich has not kept his appointment with her."