Christmas comes to Oxford Street as tens of thousands of people arrive to watch the festive lights being switched on. The programme follows the behind-the-scenes team making sure everything lights up as it should. Plain-clothes police officers on patrol have to deal with all manner of problems, from illegal immigrants to teenage shoplifters. There is a rumble underground as part of a famous public artwork is removed on the tube - will it see the light of day again? And Oxford Street in bloom - there is a look at the men who keep the area's floral displays fed and watered.