Based on a true story, Mrs. Soffel is set in Pittsburgh near the dawn of the 20th century. Peter Soffel (Edward Herrmann) is the warden of a top security prison, and his wife Kate (Diane Keaton) often comes by to read the Bible aloud to the inmates, despite her fragile health. While making her rounds, she makes the acquaintance of the Biddle Brothers, Ed (Mel Gibson) and Jack (Matthew Modine), who are sentenced to death for murder and robbery.