15 Keys 2

15 Keys 2 is the second installment to the 15 Keys series, and follows again during Aqua's timeline. It recounts Her fathers relationship with Kristine Cheney and then follows Kristine as the Protagonist.

Plot
15 Keys 2 follows a new protagonist Kristine Cheney, the girl who became Zachs girlfriend at the end of The 15 Keys. The world has been altered into a post apocalyptic earth, and must be changed back. After this happens everything resumes as normal. This is the shortest book in the entire saga.