There is an Anthropomorphic Personification of London and it is NightingalePeter often wonders if London as a whole can have a spirit, and what it would be like, but he misses that Nightingale and himself both know the city inside out and practically feel its rhythms. That is the reason Nightingale is getting younger as The Magic Comes Back. At the end of the series Peter will take over that role. He practically lays claim to the position in his "World of Cardboard" Speech to Tyburn in the first book.
Book Six will be a Tyburn centred bookIt is provisionally titled "The Hanging Tree", an old name for the Tyburn Gallows, and the other books have all hinted at an upcoming showdown between fan favourite Tyburn and The Folly (as well as with Mama Thames herself. Tyburn also has big plans for kicking over The Masquerade (which, admittedly, is increasingly ropey and thin), so this will be when it all kicks off.