On the planet Nebulon in 2120, Zack joins his school's Explorer's Club and visits Juno, a planet made of crystals, but he is less than thrilled when he is partnered with the class bully.
Zack is shocked to find a large, green, six-eyed creature sitting in his place at school one morning, but soon learns that he and the "monster" have a lot in common.
Zack and his father are invited to join the Nebulon Navigators as they set out to return a lost baby pterosaur to the Prehistoric Planet, where Zack sees animals and plants he had only read about in books.