Justin Long has joined the cast of the Robert Redford-directed film The Conspirator, according to The Hollywood Reporter. James McAvoy and Robin Wright Penn have already been cast. The Conspirator revolves around a Confederate sympathizer (Wright Penn), who was tried for the Lincoln assassination, and her defender (McAvoy). Long will play the role of a Civil War soldier who is a friend to McAvoy’s character. The film is on track to shoot in Georgia this month.