The Guardian Prince: Book Two of the Ceryn Roh Saga

Aided by a race she once believed extinct, Sabine Rhyonselle has escaped the Rüddan who enslaved her and fled Khapor. Now half a world away, she joins the Aethel prince Aodhan and his companions in a race to beat the Rüddan to the one thing that can secure Humanity's freedom: the godstone Fyrleoht.