Put me back together

'Three years passed since I lost her. It still feels as if she's going to come back any minute now. And when she doesn't, it still hurts. Like a burning fire, like an open wound, her absence makes everything a little colder. I don't know if I'll ever heal. But to hope...isn't it more painful' What's the truth behind the death of Tris? Does Four really needs to forget? R&R