Nanoo is Ollie’s beloved grandmother and an astronomer who discovered the planet Terenza in a gentle galaxy east of the moon. When Nanoo disappears on a trip to the Outback, Ollie cannot accept that she is gone. He is worried and sad and refuses to believe that Nanoo would leave him. He feels helpless, sitting around on his farm with only his faithful Labrador, Chloe, to listen to his feelings.
However, his luck changes when the Starchaser and his Star-fordshire terrier, Buddy, plot a way to get to Earth from Terenza. The boys and their dogs begin an epic adventure to find Nanoo. Their journey takes them across the Outback, up the Steps to the Moon, and into space. But will Ollie find her, and will he bring her home?