Kingdom Fall: The Elven Citadel, Book 3

The mission to destroy the citadel has not gone well Their guide took them on a journey where Queen Sara Bellfourth discovered peoples she never knew existing. Their guide, the Woodsman, assured her that there was another way into Emos. Their journey led them to a vast land that Sara did not know existed, the land of the dwarves. Dwarves were creatures of myth and legend.
Just as she thought she could trust their guide, she found herself betrayed by him and is now a prisoner of the Dwarves. Unless she can find a way out, the fate of the war, her kingdom and her beloved husband who was captured by the Emos army, will all fall the evil Queen Hellicus.