The Mountains of Mourning by Lois McMaster Bujold
This novella takes place 3 years after "The Warrior's Apprentice", right after Miles graduates from the Military Academy.
What I absolutely love about the Vorkosigan-saga is the range of topics, the variety of genres - and ultimately the very human story it tells. In this case, Miles, 20 years old and feeling on top of the world after surviving the Academy with his bones (mostly) intact, is confronted with the backwater attitudes of the hillfolk in the Vorkosigans' own district. Not everywhere physical deformities are overlooked, and infanticide because of birth defects is still common place. And now Miles, the epitome of everything feared and frowned at, is called to sit judgment in the case of a baby's murder because of a cat's mouth.
"You've established the infanticide was murder."
That about sums up what attitude Miles faces while investigating the case. But it's not just a murder investigation, it's the conflict between old and new, between stagnation and progress, between parents and children that's at the bottom of this story, Barrayar's politics and the entire Vorkosigan saga.
Miles is just as much a child of his progressive parents as he's the grandchild of a man who attempted infanticide himself. So it's not just a step into another world, it's also a step into his very sensitive past. That's quite well illustrated by the time it takes to reach the mountain village of Silvy Vale, the location of the crime. It's a time to slow down, to adapt to the different pace of things and to get settled. Because as much as Miles sits in judgment over Raina's murderer, so does the backcountry, if not Barrayar as a whole, over him. And Miles' own ideals shift - he realizes what he's fighting for... all those who didn't have the same opportunities, who didn't survive beyond infancy, and also those who still live in that backcountry, without modern amenities such as education, he owes to them that they don't get lost during Barrayar's rush for progress.
Change is a very flexible word, with many nuances. Sometimes it is born out of death and mourning... and even reaches, at a slow, at times too slow pace, into the farthest regions. And with it comes hope for a better future.