"Yes, now what was all that about? You were so damn Sherlocky yesterday all of a sudden. We'd been doing the thing together all the time, and you'd been telling me everything, and then suddenly you become very mysterious and private and talk enigmatically--is that the word?--about dentists and swimming and the 'Plough and Horses,' and--well, what was it all about? You simply vanished out of sight; I didn't know what on earth we were talking about."