Summer Term at St. Clare's is the third book in Enid Blyton's St. Clare's school series. The term is filled with the usual excitement and drama of boarding school life. The plot follows the O'Sullivan twins, Pat and Isabel, as they deal with new pupils, new challenges, and the traditional end-of-year sports events. The warmer weather and the focus on outdoor activities often lead to pranks, secret meetings, and a heightened sense of fun and rivalry among the girls.