I recently read the book "Crank," by Ellen Hopkins. In the book, Kristina is visiting her father in New Mexico. Soon after she arrives, she meets Adam, also known as Buddy. Kristina introduces herself as "Bree," her alter- ego. Throughout the book, Bree repeatedly does things that Kristina would never think of doing, including doing dangerous drugs such as cocaine and meth.

When Kristina/ Bree is still in New Mexico, she is continually getting herself into trouble. By becoming Bree, Kristina lets herself do all of the crazy things she would've never done, without thinking of the consequences. She's letting herself get into serious trouble with boys and drugs, and regrets it as soon as she becomes Kristina again.

When Kristina/ Bree gets back to Nevada to be with the rest of her family, she meets a lot of new people. First she meets Chase, and then she meets Brendan. She introduces herself as "Bree" to both of them, and doesn't act like Kristina at all. This gets her into even more trouble than she was in in New Mexico, especially because in New Mexico she could leave and never come back, but in Nevada everyone knows her.

Kristina/ Bree sees her self as two completely separate people. There is Kristina, who has good grades, gets along well with her family and friends, and doesn't do anything dangerous. Then there's Bree, who is easily bored when she isn't doing something "insane." Bree is daring, and Kristina is safe. Kristina / Bree seems to like Bree more when she is being Bree, and as soon as she becomes Kristina, she tells herself how stupid she was to do whatever Bree was telling her to do.

When Kristina/ Bree first got off the plane in Nevada, she says that "Kristina had seen it all before. Kristina was home. Bree saw it all through new eyes. Bree was a stranger." This shows that Bree had only really become a part of Kristina while she was in New Mexico with her dad, and that Bree was new to Kristina's family in Nevada.