Naked empire. Terry Goodkind. 2003.

Richard has been poisoned. Saving an empire from annihilation is the price demanded for the antidote. With the shadow of death looming near, the  empire crumbling before the invading hordes and time running out, Richard is offered not only his life, but the salvation of a people, in exchange for delivering his wife, Kahlan, into bondage to the enemy.

With the stakes higher than life and death, Richard and Kahlan face possibly the most devastating choice they will ever have to make.