A century and a half after cloned dinosaurs forced humans to move into underground compounds, Sky discovers a clue to the whereabouts of her long-missing father and ventures above ground on a quest that has the potential to save the world.

"Roommates Skunk and Badger head out on a rock-finding expedition that becomes much more dangerous than they ever expected"--

Ronnie is just a normal fifth-grader trying to pass her science class's impossible quiz on the history of dinosaurs . . . until she happens upon her neighbor-Ms. Lernin-a retired paleontologist. With the assistance of Science Magic, Ronnie and Ms. Lernin travel back through time and space to experience the Mesozoic Era firsthand. They visit three important time periods in the development of the Mesozoic Era: the Triassic, the Jurassic, and the Cretaceous....

The local police prove unhelpful when a 500-pound dinosaur skull vanishes from a secret excavation on Sage's family's ranch, so Teddy and his friends conduct their own investigation.

In this alternate history, Napoleon wins at Waterloo by unleashing a secret battlefield weapon--a legion of giant, carnivorous dinosaurs imported from the wilds of the Americas--and only fifteen-year-old Willem Verheyen stands in the way of the emperor's plan for world domination.