Billabong, a large cattle and sheep property in the Australian countryside, is home to twelve-year-old Norah Linton, her widowed father 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 holiday 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!