I do not know which of us got into the carriage first. Indeed I did not know he was in the carriage at all for some time. It was the last train from London to a Midland town-a stopping train, an infinitely leisurely train, one of those trains which give you an understanding of eternity. It was tolerably full when it started, but as we stopped at the suburban stations the travellers alighted in ones and twos, and by the time we had left the outer ring of London behind I was alone-or, rather, I thought I was alone.