An orphaned, sour-faced girl is sent from India to live with her stern, reclusive uncle in a gloomy Yorkshire manor, where she discovers a neglected walled garden and, with the help of a nature-loving boy and the revelation of a hidden key, brings the garden back to life; in restoring it she and her sickly cousin regain health, joy, and a sense of belonging, illustrating the restorative power of friendship and nature.