Who are you and what have you done with Ruth Rendell? This is a distressingly ghastly book.

Rendell's style is here and I know some of her more recent novels have been getting a bit wobbly, so I suppose I must believe that she committed the crime of this book. It improves in the last quarter but the preceding three quarters were jaw-clenchingly awful and had it not been an author I had known and loved I would not have persisted. A pastiche of Alexander McCall Smith's Scotland Street or Corduroy Mansions series, it managed to be trivial and then occasionally, in the character of Dex, downright offensive - what was she trying to say, that he was schizophrenic, autistic, damaged by abuse? Several of the stereotypes were nasty (I think she may have meant them to be funny), this was wicked.

The Saint Zita Society, a grouping of 'servants' working in posh Hexam Place and which makes a great title was utterly unbelievable. Perhaps it was by saintly intervention that despite this cardboard world there were, late in the book, several moments of frisson when the penny drops about what has happened, might have happened or what might be about to happen.

Perhaps the most annoying thing is that this is a story that could have worked. With a major re-write and a luminous cast, it might make a decent film with characters you cared about.