Brothers in Arms by Lois McMaster Bujold
Read in January 2010 as part of the omnibus edition Miles Errant.
Miles shakes the Cetagandans off the Dedarii Mercenaries’ tail and seeks sanctuary on Old Earth for repairs and recuperation. But something is rotten in London, where Miles repeatedly tries to collect the mercenary troops’ back pay and expenses. His investigation turns up a Komarran plot that threatens, you guessed it, the Barrayaran Empire at the highest levels. Believability was only stretched to the breaking point for one seemingly whimsical plot point that Miles pulled out of thin air to avoid an investigative reporter … which actually turned out to be true and bite him in the rear.
Miles managed to solve the various mysteries, save the Empire, get his mercenaries paid, get the girl, save his brother and salvage an almost enemy’s career. Too bad he missed out on touring Old Earth in all the excitement.