Michael Pryor 
Chronicles Of Krangor 3: The King In Reserve [EPUB ebook] 

Battles, betrayals and beguiling enchantments Queen Tayesha’s mad plan to rule all the Saur people is tormenting the land itself. Earthquakes, volcanoes and vast crevasses are threatening to tear Krangor apart. There is one way Adalon and his friends can halt the Queen’s plans. They must rescue a young king who has eluded the Queen’s clutches. But this mission is thrown into turmoil when the mysterious and terrible A’ak redouble their efforts to return from their magical banishment. Adalon, Targesh and Simangee must rise to challenge after challenge. The fate of the world is in their claws.