Charlie Gimbert returns home from overseas, popping up again in a new and unlikely role as manager to Murray McNally, a famous but disgraced snooker player. Murray wants Lovejoy to find him the billiards table which belonged to Mary Queen of Scots, and it seems that money is no object. A visit to Fotheringhay Castle leads on to a descendant of Mary's jailer, and then to an exhibition snooker match starring the real world snooker champion, Dennis Taylor.