Billabong, a large cattle and sheep property in the Australian countryside, is home to twelve-year-old Norah Linton, her widowed father, David, and her older brother, Jim. Norah's prim and proper aunts, who live in the city, consider she is in danger of "growing up wild" - riding all over Billabong on her beloved pony, Bobs, helping with mustering, and joining in all the holidays fun when Jim and his friends come home from boarding school. A fishing trip results in unexpected drama when they discover a mysterious stranger camped in the bush. Who is this stranger and why is he there? Norah's resourcefulness is tested to the full!