Last Term at Malory Towers is the sixth and final book in the original Malory Towers series. Darrell Rivers and her cohort are now in their final year, facing the responsibilities of being Head Girls and dealing with important exams. The story focuses on the challenges of leaving school, making difficult life decisions, and mentoring the younger girls. The book provides a sentimental farewell to the school, wrapping up the girls' journeys and celebrating their strong, lifelong friendships.