Edward leaves Bella, and tells Alice not to watch for her. Bella somehow gets involved in something criminal, like she witnessed a crime, or the Volturie wanted to have her killed. I can't remember. Anyway, they blow up her truck, and she loses her memory, and the government relocates her, but then the Cullen's happen upon her. I think her new name was Annabella. And the Cullens don't recognize her.