When fourteen-year-old Zia and her brother, Mando, find a boat cast up on the beach near the Santa Barbara mission, they are determined to make the voyage out to the far island- the Island of the Blue Dolphins- where Karana, their aunt, had been left behind nearly eighteen years before, and rescue her.

And so, with a piece of cloth for a sail, a fishhook, a compass, and no experience sailing, Zia and Mando set out in their eighteen-foot boat for the sixy-mile journey, a journey filled with danger and adventure- and a reunion.