I picked up this book from the bookshelf of my boyfriend a few years ago and couldn't put it back down. The main character is a man who is reconstructing a historic building using traditional mortise-and-tenon construction. His lady love is a psychologist who is trying to understand the entertwined minds of a pair of siamese twins. The man is convinced that the twins are evil, so very contrary to the goodness and purity of his square joints. Both man and woman are passionately and completely devoted to their subjects, which dominates their lives as extensions of their personalities. Out of this tension, the story unfolds with exquisite imagination and architectural detail. It is, for me, unforgettable.