Harriette's early adventures are told in the book 'The Lonely Shepherd' and continue in 'Jacob's Last Bite'. Now, in 'The Final Lesson', she goes on her last surprising adventure which takes place at a boarding school for boys. British security is under attack, the country is threatened by right-wing extremism, and as a history teacher at St Christopher's Private Boarding School For Boys Harriette has a watching brief which ultimately becomes one of the most challenging adventures she has ever experienced. Can the national situation be rescued from the evil which is closing in on it? And can Harriette be rescued from being immersed in it all?