She can feel the anger. And the anger is from an uncommon source. Usually Jayne is angry. Always. In fact, his anger adds to this new uncommon anger. His anger is seething, but it is normal. Mal has a tendency to get mad, but it never lasts long and is usually a pretense anyway. Zoe gets mad. But it's an OK mad. At least Wash likes it. Wash is rarely angry. We he is, it is trivial. Inara. Yes, she gets angry. But mostly at herself. Kaylee gets mad. She's cute when she's mad. She's mad now. At Simon. Simon. His anger is the uncommon anger River feels. It is a seething self-loathing and murderous hate. And River is afraid. She has felt his anger before. He is angry after botching up a conversation with Kaylee. He always feels dislike toward Jayne. But River feels both these things magnified. To an unusual and frightening degree.