I am a huge fan of GGK's work, though looked forward to this book with a little trepidation as I am not such a huge fan of teenage boys! I had recently read Robin McKinley's Dragonhaven (a very different book!), which has a teenage boy narrator, and found it heavy going. But Ned Marriner has a likeable personality, realistic but not annoying, and is a sympathetic viewpoint character. I especially enjoyed the dynamic between him and the adults around him, as he seeks both their support and his independence.
Provence is gloriously depicted, and the rented villa sounds idyllic! Into this paradise come violent events from prehistory, as mysterious figures loom, appear and threaten. There are violent scenes, but things never get as dark as, say, the events of Fionavar. I don't feel this is a bad thing though, as the characters and atmosphere are all as strong as one expects from Kay.
Many readers seem to have been disappointed by this book, and to be sure, it is not in the same class as Fionavar or Sarantium. But Kay is doing something different here, looking at the invasion of the distant past into our modern world, and the effect this has on a couple of teenagers and those who seek to protect them. As such, I think he succeeds admirably in showing how they are all forced to change their assumptions and broaden their horizons, as well as writing a thoroughly compelling story. This book could appeal to a younger audience than is usual for Kay's writing, which can only be a good thing for his continuing popularity.