SPOILER ALERT: This story contains major plot details for Thursday’s episode of ABC’s ”9-1-1: Nashville.” It’s the moment all “9-1-1: Nashville” fans have been waiting for: the origin story of Don Hart (Chris O’Donnell), his old flame Dixie Bennings (LeAnn Rimes) and his wife Blythe Hart (Jessica Capshaw). Titled “Don Begins,” the episode flashes between […]