I ask this because I'm currently reading Fever and Spear by Javier Marias, which is the first volume of the Your Face Tomorrow Trilogy. Personally it interests me just to see what sort of themes or aspects of a story the author thought was worth spreading into multiple books. I know that in some cases the trilogy designation is given by the community rather than the author itself, and either way the link between the books can be very loose.
For those with experience, what did you find in a series that you feel contributed to the exploration of themes, or anything else you might have noticed? Also it doesn't have to specifically be a trilogy. A sequel or just a series in general is fine too.
While I can't say much on Fever and Spear yet, I can give slight opinions on other series that I'm partway through.
The Danzig Trilogy by Gunter Grass: I have only read the first two books being "The Tin Drum" and "Cat and Mouse." And it's been a while since I've read Tin Drum specifically. Obviously the location of Danzig is a key factor. Cat and Mouse seems more concerned with providing a snapshot of the way the youth behaved on the cusp of Hitler's regime. It frames a boy that is clearly unconventional and seems to elucidate the repercussions of free expression during that time. The Tin Drum approaches the topic through the eyes of Oskar Matzerath who seems to represent a sort of physical and mental stagnation some German people experienced during the war. Gunter Grass is a very strange author for me because I wouldn't say he's close to being a favorite of mine, but something about the way he writes his novels makes me want to understand them more.
The Border Trilogy by Cormac McCarthy: Again, only read the first two here because I often need long periods in between McCarthy's books. Compared to All the Pretty Horses, The Crossing felt more solitary, less romantic, more meditative on the nature of family and the outcome of certain decisions. To me it really did feel like a lot of the same ingredients were still there from the first book, but expanded on in certain areas. They both deal with loss and guilt but one feels more personal and empty. Personally, I did prefer the first half of ATPH due to the nature of the conversations and moral dilemmas, some of which I still find myself thinking about, but I feel as if I'm in the minority there.
It's been a while since I've read these books, so I don't have a truly well thought out analysis, but I was curious what other people thought. Also feel free to share any that you might be interested in for whatever reason. For example I'm planning on reading Samuel Beckett's trilogy of novels as well as the Snopes from Faulkner in the future. #entertainment