Thrones & Bones: Nightborn

Karn Korlundsson is a gamer. Not a riddle solver. But in order to rescue his best friend, Thianna Frostborn, he will need to travel to the faraway city of Castlebriar (by wyvern), learn how to play a new board game called Charioteers (not a problem), decipher the Riddle of the Horn, and tangle with mysterious elves.