Made it back home ten minutes ago. Had left Watford at 5:10 pm or so. Spent all this time on the motorway, which was closed at the Edgware junction. Had to cancel two lessons, one who had to pay today, the other one a new pupil. Not very good. And I'm knackered. I can't believe I just spent four hours sitting in a stationary (yes, I did write 'stationery' at first :P) car crawling along at 0.2 mph on the motorway. Whatever it was, must have been quite serious.