The Diamond Throne by David Eddings Paperback 1990 GD

THE QUEEN'S CHAMPION

Sparhawk, Pandion Knight and Queen's Champion, returns from a long spell of exile to find his native land overrun with evil and intrigue - and his young Queen grievously ill. Indeed, Ehlana lies magically entombed within a block of crystal, doomed to die unless a cure can be found within the year.

But as Sparhawk and his allies – who include Sephrenia, the ageless sorceress, and Flute, the strange and powerful girl-child - seek to save Ehlana and the land, they discover that the evil is even greater and more pervasive than they had feared…