Margaret Thompson, an 8 widow, has just lost her husband, Edward

Margaret Thompson, an 8 widow, has just lost her husband, Edward, after 60 years of marriage. While going through his belongings, she stumbles upon a dusty, unopened envelope hidden in the back of a drawer. It's a love letter, but it’s not addressed to her. Instead, it's written to a woman named Evelyn, dated two years before Margaret and Edward even met.