When mysterious new boy Ryan Westland shows up at her school Eden Anfield is intrigued.

On the face of it, he's a typical American teenager.

So how come he doesn't recognise pizza and hasn't heard of Hitler?

What puzzles Eden most, however, is the interest he's taking in her. As Eden falls in love with Ryan, she stumbles across a book in Ryan's bedroom - a biography of her best friend - written fifty years in the future.

Unravelling Ryan's secret, she discovers he has one unbelievably important purpose ... and she might just have destroyed his only chance of success.