The Nanotech War

Voyager encounters the Chiar, a civilization that turned to nanotechnology instead of the stars, weaving nanites into every corner of their bodies and society. Caught in a bitter civil war, one faction sees Janeway's ship as a shortcut to real power: harnessing nanite technology to seize the Borg's assimilation abilities for themselves, an experiment that spirals out of control faster than anyone expects.