A novel concept, in my experience, but the writing just isn't that interesting. After the apocalypse, remaining scientists find a way to genetically remove all emotions from humanity except fear. Almost 500 years later, a few people find a way to restore those emotions. I can understand that a massive influx of previously unknown emotions could drive a person to catatonia, and even someone who was functional might prefer their previous state, but I'd really like a little character development before somebody goes off and does something stupid! They've been given emotions
and even if, as more than one character says, that interferes with rational thinking, that doesn't mean they've become stupid!