They remained there nearly half an hour, when Kirk emerged, and, bidding good night to his friends at the kerb, re-entered the taxi and drove to Whitehall Court, that large block of flats which overlooks the embankment close to Northumberland Avenue. Here the liveried porter saluted him respectfully and carried his bag to the lift, up which a few minutes later he disappeared.

In my mechanic’s attire I was now placed at a great disadvantage. Any inquiry I might make of the gorgeous attendant would, I knew, only arouse suspicion, but a thought instantly occurred to me. The friendly driver of my taxi, believing that I, a motor man, had been swindled, might perhaps help me. We had pulled up at the corner where, in a few brief sentences, I now explained to him that I was anxious to know whether Kirk resided there in his own name.

“I’ll inquire for you, mate, if you like,” declared the taxi-driver cheerily. “You just wait here.”

And while I mounted guard over his cab, the red-moustached driver went along to the entrance to the flats. I saw him in conversation with the lift man, and when presently he returned he said:

“The gentleman just gone in is Mr Seymour, who lives on the third floor. He’s abroad very often, it seems, and is only just back. He’s lived there a couple of years.”

Now I recollected that Kirk, when we had sat together that first night in Bedford Park, had told me that he possessed another home, and I had now run him to earth.

Whitehall Court is an expensive place of residence. Apartments there seemed far beyond his income as he appeared when he passed my house, shabby, broken-down, and often hungry-looking.

I gave my friend the taxi-man half a crown beyond his legal fare and dismissed him, afterwards walking as far as the entrance to the National Liberal Club, trying to decide how next to act.

To face the fellow boldly and unflinchingly was, I recognised, the only way in which to gain the knowledge I sought. Yet in the garb of a mechanic, was I not much handicapped? Nevertheless, I walked back, and, finding the hall-porter, gave my name as Flynn, and asked to see Mr Seymour upon important business.

After a wait of nearly ten minutes a man in uniform came and ushered me up in the lift to the third floor, where, having traversed a long, thickly-carpeted corridor, he opened a door and allowed me to pass across the small well-furnished hall of the flat into a sitting-room, where I found myself again face to face with my mysterious neighbour.