Well I stopped on the way home for this piccy, leaned the bike against a hedge, just like I normally do.
Took the pic, then looked at the bike... branches from the hedge must've knocked the chain off the chainring. That was a delay I wansn't expecting!!! Still, it went back on a lot more easily than I was expecting. Still got oily mucky hands though. Good job I packed some tissues in my pannier bag last year! :o)

nb. Brrrrr - bit chilly for cycling!