In this heartwarming and hilarious reimagining of The Strange Case of Dr. Jekyll and Mr. Hyde, a secret potion accidentally turns eager-to-please eighth grader Jaclyn into Jackie, a goblin-like monster who'll do anything to win at everything she does--no matter how much chaos she creates along the way.

Jaclyn Hyde is almost perfect. Whether she's baking cookies for her classmates, building a replica Mt. Vesuvius for the science fair, or practicing her lines for Fog Island: The Musical, she almost never makes mistakes. When she discovers the last batch of perfection potion in an abandoned laboratory, Jaclyn decides that being almost perfect isn't perfect enough anymore.

But Jaclyn quickly discovers that the potion turns her into Jackie, a goblin-like monster who'll do anything to make sure Jaclyn comes out on top. Suddenly, she's wreaking havoc on the school play, stealing someone else's brownies to pass off as her own, and that's just the beginning. If Jaclyn wants to save her school, her friends, and herself from her perfectly horrifying alter-ego, she's going to have to screw up her courage and risk it all--even if that means admitting that she never was as perfect as she seemed.