What an experience, reading this, the very last Diana Wynne Jones book. It's always hard to compare DWJ books, since every one is vastly different from the next... My favorites are and always will be the Chrestomanci series, though I also have a soft spot for Howl, and enjoyed Enchanted Glass and several others of hers I've read. As it is, I have only read a fraction of her works and have never been disappointed by a one of them, and that stands true for this story as well. 
 There is a... difference to the tone of this story. A wistfulness, a simplicity, a glimpse back into our own childhood when the stories we loved didn't have to be complex or twisting or convoluted to be enjoyable, they just had to have interesting characters and an adventure. And that is exactly what this story delivers. 
 Travel with Aileen as she goes from believing herself to be an utter failure and a somewhat sheltered and naive child to the heroine she was always meant to be. As I read, I almost felt as though I was growing up with Aileen, her perspective shifts and changes so gradually as the adventure progresses, you and she will almost miss it. 
 A tremendous thank you to Ursula Jones for finishing this story. It was obviously an act of love on your part to do this for your sister, and it is obvious that you took great care with finishing this story and staying true to her style, voice, and vision. As a life-long fan of your sister's novels, thank you for ensuring that we all got one last book from Diana.