This is a free-writing exercise. You don’t need to show it to anyone or feel any pressure. It’s just something to give you a start sometime when you’re feeling dry. It could be incorporated into a current work-in-progress or spark a new idea. Or maybe it’ll just end up in the trash. But at least try it.
She/he refused to open the registered letter. She/he knew what was in it.
Concentrate on creating the tension of the moment. How will you convey it without overtly saying it? What physical or emotional cues can you give?