Class X has a reputation. It is the kind of reputation that makes teachers run out the door screaming. Literally. Arlo is just trying to survive the school day, but when the latest substitute teacher arrives, he knows things are about to get weird. Meet Mrs. Ogg. She is definitely not your average teacher, and her idea of a fun field trip is completely out of control. When Mrs. Ogg announces a class trip to the local zoo, Arlo thinks he needs to step up and keep his wild classmates from causing total disaster. But keeping Class X in line is the least of his problems. Mrs. Ogg forgot to mention one tiny detail about their destination. They are not going to see penguins or monkeys. They are visiting a secret zoo filled with living, breathing dinosaurs. Now, Arlo has to manage a class of troublemakers, figure out his bizarre new teacher, and somehow avoid becoming a midday snack for a hungry prehistoric beast. Grab your permission slip for a hilarious adventure packed with gigantic reptiles, laugh-out-loud classroom chaos, and a field trip you will never forget.