Jane has a cat called Furlong. Every day, he walks to school with her and Andrea, her friend. Then he takes his own way home. He's so furry that some people say he looks like a feather-duster, but William, the new boy, says he looks like a loo-brush. However, William is trouble from the moment he appears. He causes a division in the class and sets the boys against the girls. When he threatens Jane with violence, it seems as though the only way she can escape him is to take Furlong's secret path, along the wall, and into the unknown.