I found The Islands of Chaldea in the bookshop yesterday.
Diana Wynne Jones is one of my recently discovered but very much loved authors. She is no longer with us so I was surprised to see a new book and then noticed that it was 'completed by Ursula Jones'. Oh dear I thought. My experience with other authors collaborating or continuing the work of a well known author hasn't been very good. However I looked a little closer and discovered that Ursula is one of the younger sisters of the author and the family had agreed that she should attempt to complete this last novel. There is a very touching afterword where this is explained and my fears were calmed.
I bought the book and am looking forward to a little more from Diana Wynne Jones.