Tara is a 10-year-old girl living on Earth in the year 3053, and her grandfather lives on the moon.
Whilst watching her favourite television show, Tara is interrupted by an emergency broadcast warning of the destruction of the moon. She races to the moon to warn her grandfather, only to find him missing!
On the moon, she meets Toby, a strong-willed and adventurous young boy with information of her grandfather's disappearance. Tara's fears for the safety of her grandfather grow as she hears the information Toby has to offer, but his adventurous nature and his willingness to help brings her some hope.
As the children begin their search for Tara's grandfather, an unlikely friendship forms between human and alien, taking them on the journey of a lifetime through space to find him. Their adventure takes them from planet to planet, where they meet new friends and become selfless heroes.