A charming mystery albeit a little heavy on the chess theme; I don't play the game and it was a little much, but still intriguing, with an ending I didn't forsee. I took it on a trip and it was a good way to occupy the time.
Amazingly I found the depiction of the chess problems (I'm nothing more than a novice player who hardly ever beats the game in the Windows version on my PC) more interesting than the plot. I thought the heroine was not that interesting (although her occupation is.) Unlike The Shadow of the Wind by Carlos Ruiz Zafon which brought Barcelona to life, Madrid was just a vague background to the story here. I also thought a representation of the painting would have been a nice touch (the copy I had showed chess pieces on the cover.) Never did manage to finish it, either, so maybe it got better after the first half?
I had not read this author's work before, but I'm very impressed with his writing. Even though chess played a major role in the plot he made it understandable for someone with only a rudimentary understanding of the game. I thoroughly enjoyed this read!