natasha basset is britney.d to get inside her head, what do you think she was going through? >> i think she got into something at a very young age that almost cannibalized her. >> reporter: she went all red leather raunchy. ♪ i'm not that innocent >> reporter: oops. an early smash, britney was just 18 years old. >> seeing her as sort of a prisoner of celebrity, she can't go anywhere, can't do anything without having protection, you know. it's like living in a glass box. >> you're not trashing her in this? >> no, no, absolutely not. this is a love letter to britney. >> reporter: but still a totally unauthorized bio-pic. a spears spokesperson telling us, britney will not be contributing to the project in any way, shape or form, nor does it have her blessing. >> how did that play in the back of your mind? >> it's always difficult to play someone who's still with us and can view the work you're doing. you just want to do them justice. >> reporter: in the pantheon of stars given the lifetime movie treatment, whitney