Gordy has been stuck in a starship so long, he's outgrown his space boots. Nothing fits anymore, and he's still growing! He curls up on his hammock with his black cat Spooky. Gordy has never felt so alone.


When Gordy and his cousin Virginia are caught in a solar storm, the teenagers find refuge on the icy Blue Grannus moon. Gordy hears the story of how his parents met and learns that his name, Gordon, means "guardian," a fitting name for an ecologist. Pirates and traders claim to know his mom, who has been missing for years. Rumor has it, the Mushroom Man of Grannus Springs, knows even more about her.


Gordy and Virginia volunteer for a trading mission, a dangerous trek across the shifting delta ice and deep into the heart of the ice caves, to trade with the most famous mushroom cultivator of the galaxy. After all, space travelers need all sorts of mushrooms for terraforming, for eating, for medicinal use, and for ecosystem restoration. This brings Gordy face-to-face with a man he has never met, his father! And one step closer to finding his long-lost mom.
Meanwhile, heavy drilling at the mines poisons the colony's drinking water and sets off an earthquake, cracking the ice. Gordy flies the villagers out of the collapsing cave in a caravan of gyrocopters. Their mission becomes stopping the destructive mining activity and applying mushroom technology, myco-filtration, to detoxify the water.


Finally, Gordy says goodbye--temporarily, he hopes--to his dad, and takes off on the journey to find his mom and put his family back together again.