Harry thinks he's too old for his bucketful of dinosaurs, but they think he's wrong! He looked after them when he was little and now they want to stick by him--forever . . . When a mysterious set of plastic dinosaur cards appear on his key-ring, Harry discovers he can call on an army of Back-Up Dinosaurs. Just a rub with his finger calls up some MONSTER-sized muscle! In this adventure, Harry and his friends are kayaking when they discover someone is stealing rare birds' eggs. But there's a SURPRISE in store for the thief!