Lords of Avalon: Knight of Darkness

Varian duFey may be the son of evil Adonai sorceress Narishka duFey, but he turned his dark heritage to the side of good, acting as Avalon's most deadly assassin. Though hated and mistrusted by the other knights whose cause he shares, when someone begins killing Grail Knights, Merlin sends her darkest knight on a quest that leads him directly to his mother's door… and to a hag named Merewyn, who is more than she seems.