Captain Varro of the Fourth army is about to have the worst day of his life. Wounded in battle and fearing for his life and his future, he stumbles upon a plot that reaches deep into the past and into the roots of everything in which he believes. Accompanied by a young engineer from his unit and the daughter of his commander in chief, he begins to unpeel layers of treachery and murder that threaten not only himself, but the people that he loves. Ironroot is a tale of treason and revenge set in the world of the Interregnum, some twenty years after the events of that book.