It’s summer, 1950 and for 11-year-old Sophie, Camp Latona on Gambier Island promises to be pure bliss. Swimming, hiking, learning to canoe, it can’t get better than that, even if she does have to sneak in her favourite Star Girl comics. But Sophie has to buddy up with a strange, unfriendly girl named Ginette and things go sour. Ginette doesn’t like swimming or hiking, or anything else about camp, except canoeing. Soon, Sophie learns that Ginette has her own secrets and worries.
When Ginette tries to escape from the island in the middle of a stormy night in a canoe, Sophie has to call upon her courage as Star Girl, and rush to Ginette’s rescue. She soon realizes that she’s going to need a bigger dose of Star Girl pluck than ever to get Ginette and herself back safely on dry land.