Mary Stewart has long been one of my favourite authors. She writes with clarity, humour and lyricism, her characters are engaging, the story interesting and well researched. The Spanish Riding School in Austria is a major part of this story, and well integrated. The only issue I have with this particular book is the chase scene, which seems interminable. Usually Stewart maintains tension admirably, but this scene is so long, attempting to sustain tension while describing every move in exhaustive detail, examining motivation, taking in the scenery, explaining the feelings of the narrator through every minute motion, that it becomes more than a little tedious.
I think the book is a lovely read apart from this glaring flaw, and was involved enough to want to know the resolution. But I am unlikely to reread this book as I do her others. If you are a Mary Stewart fan, then you will likely still enjoy the book, but don't make this your first try of her work. She has many other lovely works to choose from.