Twelve-year old Jodie Jackson lives with her father above their boatshed in Serpentine Bay in Sydney. Jodie and her best friend Sarah are targeted at school by a bully. Jodie stands up to her but Sarah suffers from anxiety because of it. Jodie suggests that Sarah tell her parents about her worries.
Jodie misses her mother who has died the year before especially as there is a Mother/Daughter lunch at school. She works at her grandmother's spiritual shop to earn money for an excursion and invites her grandmother to the lunch.
Jodie sails her little boat around the harbour, exploring islands and bush areas and goes to Crater Cove, where there are old shacks from the depression era that she wants to sketch for art class.
She discovers a homeless girl hiding there and learns that the girl is a vet student studying at university on a scholarship but with nowhere to live.
Jodie sees smoke in the sky and hears the news report about a fire near Crater Cove and worries about the girl. Jodie is unable to contact her father or her grandmother, so she takes her father's runabout, even though she is unqualified.
Jodie tries to land but the smoke is too thick to see. Her motor dies and she drifts closer and closer to the rocks but the water police appear and start to tow her boat back to safety.
As they tow her away Jodie notices Serena waving for help from the shore and the water police rescue her. They take both girls back to Jodie's house and her father is very relieved at seeing her, but also cross that she took out the runabout. Serena is invited to stay at Jodie's house until they sort out her accommodation.
The next day Jodie's grandmother falls and fractures her ankle and goes to hospital and Jodie is afraid she won't be able to come to the Mother/Daughter lunch.
Jodie finds that she is missing thirty dollars when she goes to school to pay for the excursion. She confronts Serena who admits that she took it to buy some medicine for an infected cut from an oyster shell. She was planning to replace it later.
Jodie is angry but when she sees Serena's infected leg, she understands.
