This is the story of a new country-of the days when Captain Arthur Phillip was made first Governor of New South Wales and began to build the town of Sydney, It is a sequel to 'John of the Sirius', wherein John traveled with his family to Botany Bay.
John plays his part in founding the new colony: he explores the backwoods with Governor Phillip to find fresh water, and helps to build a home for Mamma and Papa and a 'cubby' for his sister Sue. He and Sue, too, help Mamma to sow seeds in the garden so that later they shall have fresh fruit and vegetables. He catches a baby 'hopping animal', makes friends with the First Australians, and finds again his friend with the cheeky grin.
Many of the incidents in this story really did happen-the others might well have happened to a boy like John.