The Justiciar Sarantian is sent to Tarnagh, a remote barony in the crumbling Republic of Kandarra, where a band of black-armoured riders wield weapons and armour of seemingly arcane power are killing nobles, officials, clergy and commoners alike, yet no clear pattern links their victims. As fear spreads and political tensions rise, Sarantian must determine whether he is facing a supernatural threat – or something far more dangerous.