Miles Errant, written by Lois McMaster Bujold and published in 2002 by Baen Books, is an omnibus edition book from the Vorkosigan Saga consisting of the two novels Brothers in Arms and Mirror Dance as well as the novella "The Borders of Infinity".
It covers a time period shortly after Miles, Mystery and Mayhem when Miles Vorkosigan is established in his first career, as Admiral Naismith of the Dendarii Free Mercenary Fleet and is particularly concerned with events as they relate to his newly discovered clone-brother Mark Vorkosigan.