I came across a very old friend yesterday - The Last Houseparty by Peter Dickinson is a minor master piece: there are some things there that have been done with quite extraordinary skill and force. Quite out of the place in a "mystery story" (as silly as it is in many ways to say this). The Remains of the Day and Atonement do have genealogies. What got me engaged all those three decades ago were naturally the themes of childhood, friendship and sex (being then in the process of messing the two latter ones up, having already done the first one in) that are so effortlessly, economically and beautifully portrayed. But I suppose most of all it was history, personal and universal, in all its complexities, that was the main thing. One of those seminal few books that have gotten me addicted to the endlessly complex process that is interpreting the past, personal and universal.
