Science girl extraordinaire Halley Harper can't believe she is on live TV, until disaster strikes forcing her to grow up and act like the eleven year old she almost is. But why does she still feel stuck in the middle-too little for some things and too big for others? To prove how responsible she is, she offers to babysit her little brother Ben. But that ends up being a disaster too! To make matters worse, their family is moving right before she starts middle school, taking her away from everything she loves: her best friend Gracelyn, her treelab, and life as she knows it. At least she always has Camp Eureka, and that will never change. But will a secret admirer alter her friendship with Nathan? Will she get along with the dinosaur-loving shy new girl? Can the fossil she discovers rock climbing be the key to getting life back the way it was, or will she realize that, no matter what, life always changes?