Another adventure with Onty the brontosaurus and his mate Mutzy the muttuburrasaurus. This time, they are in the school cadets and go on a combined camp with other school cadet groups to a place called Reptilia Park. This park has a reputation for being extremely hot during the day and extremely cold at night.

Onty and Mutzy learn a variety of new skills and put them into practice, make a whole lot of new friends and do wonderous things. They are at "war" with another school called Mount Sapphire School and their new found skills are put to the test.