In the upcoming film Woman Walks Ahead, Michael Greyeyes plays famed warrior and holy man Sitting Bull, while Jessica Chastain is Caroline Weldon, his confidant and portrait painter. Both Greyeyes and Chastain have had the fortune of playing multiple historical figures during their careers, an accomplishment many actors would kill for. While promoting the film at the Toronto International Film Festival, they took a moment to share some advice with aspiring actors on the roles they should study.