Legacy by James Schmitz

Ancient living machines that after millennia of stillness suddenly begin to move under their own power, for reasons that remain a mystery to men. Holati Tate discovered them—then disappeared. Trigger Argee was his closest associate—she means to find him. She's brilliant, beautiful, and skilled in every known martial art. She's worth plenty—dead or alive—to more than one faction in this obscure battle. And she's beginning to have a chilling notion that the long-vanished Masters of the Old Galaxy were wise when they exiled the plasmoids to the most distant and isolated world they knew....