Jill Jekel has always obeyed her parents rulesespecially the one about never opening the mysterious, old box in her fathers office. But when her dad is murdered, and her college savings disappear, shes tempted to peek inside, as the contents might be the key to a lucrative chemistry scholarship. To improve her odds, Jill enlists the help of gorgeous, brooding Tristen Hyde, who has his own dark secrets locked away. As the team of Jekel and Hyde, they recreate experiments based on the classic novel, hoping not only to win a prize, but to save Tristens sanity. Maybe his life. But Jills accidental taste of a formula unleashes her darkest nature and compels her to risk everythingeven Tristens lovejust for the thrill of being . . . bad.