Miles, the son of a powerful Vor family, is driven to succeed. He's smart, intelligent, and politically saavy. By birth, he should be assured a place in the ruling class when he reaches maturity. So, what's the problem? Miles was injured when his parents were victims of a terrorist attack while his mother was pregnant with him. His brittle bones break at the slightest pressure and cannot be replaced with synthetics until he reaches the end of his growth. The people of Barrayar have a fear of genetic defects and many people condone killing all children who are not 'perfect'. A practice that Mile's father has been trying to discourage in his province. In "Mountains of Mourning", Miles is authorized to find the person who killed a newborn child who was born with a treatable genetic disorder. Imagine the locals 'joy' to find a 'mutie' has been sent to try one of them for doing their best to preserve their genetic purity. Miles uses his intelligence to overcome the obstacles in his path. While everyone thinks he has been given every honor due to his position, Miles knows that he's earned every pat on the head, every medal, every good grade, every advancment that he has ever received. Miles is not perfect. He struggles and rails against the system, his body, and the attitudes of those around him. His continuing struggle to achieve his own goals and to make something of himself -- make him a character that I, as a reader, can sympathize with. I think what makes this series so addicting is that readers feel deeply about the main character. We become emotionally involved in his life -- we cheer him on. We want him to succeed against the odds because the author doesn't cheat -- Miles takes his beatings and goes on. An example that many of us find reassuring.