Mirror Dance

Not everyone would envy young Lord Miles Naismith Vorkosigan, even though he had formed his own mercenary fleet before attending the naval academy, and even though his mother was the beautiful Cordelia, the ship captain who has taught the Lords of Barrayar much about the perils of sexism. Even the fact that Miles is the third in line to the throne and personally owns a major chunk of his home planet would not tempt any normal person to change places with him.
When assassins came to rid the world of his father, his mother, pregnant with Miles, was in the line of fire, and Miles was but an egg for the omelet in an all too literal sense. Thanks to heroic medical intervention, Miles survived his near fatal brush with war gas - as a pain-filled dwarf with bones as weak and brittle as some malign composite of chalk and glass. Miles is often mistaken for a mutant by his mutant-loathing countrymen.