Meet my neighbours

Twenty years ago London's Notting Hill was a shabby but cool West Indian neighbourhood. Now it's a chi-chi 'magical glade', inhabited by Tory MPs, billionaire financiers and yummy mummies whose shenanigans are set to be exposed by Rachel Johnson, sister of Boris, in a roman a clef that's already causing a stir. She gives Carole Cadwalladr an intimate guided tour.