When Jamie, Tom and Wanna decide to hunt for prehistoric minibeasts they get more than they bargained for. There are no such things as minibeasts in the Permian - just megabeasts! As the boys run away from the enormous dragonflies that are dive-bombing them, they find a cave to hide in. But what they don't realize is that the cave is home to a giant spider and they're caught in its web. Will the boys and Wanna be able to get free? There's not much time . . . as today is the day of the end-of-the-Permian mass extinction event!