Mary is nine years old and partially-sighted. She dislikes being called partially-sighted because it makes her feel as if she is 'only part of a proper person'. Her parents and her gran over-protect her, and she is never allowed out alone. One afternoon when Mary is recovering from flu, her gran falls asleep, and Mary takes the daring decision to make her own way to the shop nearby. She copes well until two men come into the shop intent on robbery, and Mary is taken hostage. The following scenes of terror are realistically drawn, but in spite of her fear, Mary finds she can make mental notes about where she is and what is going on around her. One of the two men is kind-hearted, but the leader is truly terrifying. He carries a knife, and when Mary escapes through a window of the basement flat where she is being held, the suspense and menace of his chase is hair-raising. When the men are caught, Mary is the heroine, and her parents learn to accept her need for more independence. A first-rate thriller wherein Mary's partial-sightedness has actual advantages. Short (only 90 pages) and contains a number of black and white illustrations.