My Strangest Case by Guy Boothby

I flatter myself that I am a man who is not easily disconcerted, but for the second time that day I was completely taken aback. I had watched that cab so closely, had followed its progress so carefully, that it seemed impossible Hayle could have escaped from it. Yet there was the fact, apparent to all the world, that he had got away. I looked from the cab to the cabman and then at my own driver, who had descended from his perch and was standing beside me.

"Well, I wouldn't have believed it," I said aloud, when I had recovered somewhat my astonishment.