HEARTBURN — “’Tis the season to be jolly.” It’s also the season to miss people. Nora Ephron is someone to be missed. She could make us laugh at our necks, and at almost anything. Her novel, Heartburn (a barely fictionalized account of the end of her own marriage), even manages to make us laugh at divorce. Why she turns a sad, disturbing, and even enraging reality funny is an interesting question.” Divorce isn’t a laughing matter. For Rachel Samstat, Heartburn’s betrayed wife, it’s certainly not funny that her husband’s having an affair with a woman who just came to dinner and asked for her...