In the 1880s, Stanislas (Stas) Tarkowski, a fourteen-year-old Polish boy, and Nell Rawlinson, an eight-year-old English girl, live in Port Said, Egypt, while their widowed fathers work as engineers on the Suez Canal. When their fathers are away, Stas and Nell are kidnapped by Arabs as part of a rebellion against British rule.

Once captured, the children are forced to travel through the Sahara Desert, and they face all manner of obstacles, from heat and hunger to disease and deadly animals. Resourceful and determined, Stas and Nell manage to stay alive, stay together, and escape their captors. Now they must undertake their own arduous journey through unexplored and wild regions to reunite with their fathers.