V puts Evey into a likeness of that place where V went. he gave her that note that was from the person in the next cell. he tortured her, etc without her knowing that it was him. he did it to make her tougher, to giver her the power she needed in order to fight with him. he led her to believe she was being held captive and that shewas going to die. in that way, V created a truth for Evey by imitating his own past. the place wher Evey went wasnt actually real, but for her it was.