On the 21st January J. K. Rowling changed her Twitter header to give us another clue about the upcoming Strike instalment The Running Grave. Beatrice Groves, Research Lecturer and tutor at Trinity College, Oxford, and author of Literary Allusion in Harry Potter, has written a Hogwarts Professor Guest Post: Round Tower Churches and Rowling’s New Twitter Header. Join Prof Groves as she delves into the history and myth of the distinctive Round Tower Churches of East Anglia, and that of Aylme...