Alastair Reynolds - House of Suns (2008) (Lee Reading)

Six million years ago, at the dawn of the star-faring era, Abigail Gentian fractured herself into a thousand male and female clones, which she called shatterlings. But now, someone is eliminating the Gentian line. Campion and Purslane-two shatterlings who have fallen in love and shared forbidden experiences-must determine exactly who, or what, their enemy is, before they are wiped out of existence.