Vorkosigan Saga # 5.1-5.3: Borders of Infinity by Lois McMaster Bujold

Hugo and Nebula Award winner Miles Vorkosigan in all his guises: prodigal son, back-country judge, lover, spy, diplomat (not his strong suit), strategist, scapegoat, mercenary commander, and—always—hero.
This volume contains three novellas: The mountains of mourning, Labyrinth, and “The borders of infinity”; in addition to a story framing all three into a plot to court-martial Miles on trumped-up charges.