It's that time of year again.
The nights are rapidly drawing in. Jack Frost has paid his first visit of the season, making the roads glisten and the pavements sparkle. The scent of bonfire smoke is dying away, and fireworks no longer (or at least rarely) illuminate the sky. Coke, John Lewis and now Sainsbury's have all started their battle for the crown of the best festive TV ad. The last remnants of autumn have fluttered away, making way for winter.