This is book number 5 in the Freehold series.
The Prescot family were miners. At one time, they were contracted to develop technology for a mineral-rich but uninhabitable system. Gradually, all the investors shied away. Then the Prescots broke through with the technology needed to exploit entire planets, and incidentally develop domed playgrounds for the perversely rich, including indoor ski slopes and cable cars over megavolcanos, casinos and rides. This created the economic problem of being the richest people in the universe, having more money than most governments and effectively unlimited resources. Money is a small blessing when enemies are quite willing to spend billions for the chance at trillions. Bryan Prescot and his daughter might as well have targets painted on their backs for the thugs, kidnappers, and assassins their competitors would throw at them. Bodyguards were necessary--Highly trained bodyguards who could be bought once and be utterly loyal no matter the circumstances. The altercation comes to a head inside the domes and mines of Govannon, with their enemy desperate to do anything to save their own lives, now that the gloves are off. Caron Prescot has only six bodyguards against an army, but she has two aces in the hole: The miners are on her side, and Elke, Ripple Creek's psychotic demolition expert, has a nuke. The problem with Elke having a nuke is that Elke will use it.