The Reader of Acheron (The Slaves of Erafor)

Book One of the Slaves of Erafor series: Reading is forbidden, and the penalty for non-compliance is a life of slavery enabled by the forcible administration of a mind rotting drug. Yet, there are those possessed of the will to seek illumination. Kikkan, a former slave on the run, and Quillion, a mercenary and self-taught scholar. Together they seek out a small bad of rebels living in hiding who offer the promise of a better world. Their leader is a mysterious figure known only as The Reader of Acheron.