Rachel White and Darcy Rhone have been best friends since childhood. They've shared birthdays, the horrors of high school and even boyfriends, but while Darcy is the sort of woman who breezes through life getting what she wants when she wants it, Rachel has always played by the rules and watched her stunning best friend steal all the limelight.

The one thing Rachel's always had over Darcy is the four-month age gap which meant she was first to being a teenager, first to drive, first to everything ...but now she's about to be first to thirty.

And Darcy still has a charmed life.

On the eve of her thirtieth birthday, Rachel is shocked to find herself questioning the status quo. How come Darcy gets a glamorous job at a PR firm and the perfect boyfriend, while Rachel grinds away at her despised job as an attorney and remains painfully single. Is it just luck? Or, looking back at their friendship and their lives together, is it a bit more complicated than that?

Then an accidental fling complicates everything, and it's time for Rachel to make a few hard choices. And she's suddenly forced to learn that sometimes true love comes at a price ...