Caves of Glass By C.A. Gray – Silver Dagger Book Tours. Genre: Epic Fantasy. The illegitimate son of a peasant, Rion of Tryferos has very limited prospects with only one remarkable talent: when he plays the lyre, he ushers in the supernatural balm of peace to all who hear. This turns out to be his ticket into the palace, where he nightly plays for the restless, rejected king. King Hector of Tryferos is paranoid, because he knows his days on the throne are numbered. What he doesn’t know is that his anointed successor is Rion.