It's time to unpack the spaceship for another intergalactic adventure! The members of the Space Brigade have received an intruiging letter from the Commander-in-Chief of the Planet of Shobble. He mentions 'grave danger'... When they land on Shobble, they soon discover that the planet has a dark secret - most of the population are slaves, forced to mine for marshmallow and drill for chocolate. But a teenage girl called Topaz is encouraging the workers to rebel, and the Commander-in-Chief wants the rebellion sqaushed. Soon, Nicola Berry and her friends are crossing infested rivers, snowy swamplands and frozen seas. Along the way, they'll learn new skills, meet unexpected creatures - and change Shobble's history forever.