As my lips framed a particularly unpleasant expletive a bell rang sharply, and I turned to see a taxi, which had that moment been dismissed.

“Oxford Circus,” I cried, flinging open the door.

A moment later we were near enough for me to indicate the large limousine and to instruct my driver to follow her.

As we swept into Regent’s Park, I began to wonder whether I should not have been wiser to drive to Bond Street and buy a new hat.  By the time we had been twice round the Ring I had no longer any doubt on this point; but my blood was up, and I was determined to run my quarry to earth, even if it involved a journey to Hither Green.

More than once we were almost out-distanced, three times we were caught in a block of traffic, so that my taxi’s bonnet was nosing the limousine’s tank.  Once I got out, but, as I stepped into the road, the waiting stream was released, and the car slid away and round the hull of a ’bus from under my very hand.  My escape from a disfiguring death beneath the wheels of a lorry was so narrow that I refrained from a second attempt to curtail my pursuit, and resigned myself to playing a waiting game.

When we emerged from the Park, my spirits rose and I fell to studying what I could see of the lines of the limousine, and to speculating whether I was being led to Claridge’s or the Ritz.  I had just pronounced In favour of the latter, when there fell upon my ears the long regular spasm of ringing which is a fire-engine’s peremptory demand for instant way.  Mechanically the order was everywhere obeyed.  The street was none too wide, and a second and louder burst of resonance declared that the fire-engine was hard upon our heels.

The twenty yards separating us from the limousine were my undoing.  With a helpless glance at me over his shoulder, my driver pulled in to the kerb, and we had the felicity of watching the great blue car turn down a convenient side street and flash out of sight.

The engine swept by at a high smooth speed, the traffic emerged from its state of suspended animation, and in some annoyance I put my head out of the window and directed my driver to drive to Bond Street.

I had chosen a new hat and was on the point of leaving the shop, when a chauffeur entered with a soft grey hat in his hand.  The hat resembled the one I had Lost, and for a moment I hesitated.  Then it occurred to me that there were many such hats in London, and I passed on and out of the door.  Of course it was only a coincidence.  Still....

Opposite me, drawn up by the kerb, was the large blue limousine.

The next moment I was back in the shop.

“I rather think that’s my hat,” I said.

The chauffeur looked round.