The Warrior's Apprentice

Barred from the military academy by the brittle bones a poison-gas attack left him with, Miles Vorkosigan improvises his way into command of a mercenary fleet he never meant to build, bluffing, borrowing, and outright inventing his way across the wormhole nexus with only a loyal armsman and his own relentless nerve. It is the book that turns a physically fragile teenager into one of science fiction's most irrepressible strategists, launching the Vorkosigan Saga's long run of comic disaster and real stakes.