Rhyn's Redemption (Book III, Rhyn Trilogy)
Katie and Rhyn are in a race to free Katie from the underworld, before Death claims her soul and that of her child. When Katie’s guide in the underworld disappears, she must seek out Death's fortress in order to try to escape through the portal leading back to the mortal world. Rhyn struggles to control his demon powers. Demons follow him as he seeks out Death to make a deal for Katie's life.