In the unremarkable town of Menominee Springs, Wisconsin, lives a twelve-year-old explorer named Martin, who one day stumbles across something remarkable. It's an egg. But not just any egg-a dinosaur egg. And a week later, Martin becomes the proud parent of a Tyrannosaurus rex! As the summer unfolds, Martin finds it harder and harder to keep Rufus hidden from rest of the world. And then it gets ugly. Can Martin save Rufus from his parents, his neighbors, and most importantly, the owner of the town carnival? With the help of his best friend, Audrey, and his science teacher, Mr. Ekhart, Martin must uncover his inner hero and find Rufus a home, even if it means losing the one thing he's come to really care about.