Archibald the Professor of Arcane Knowledge has some unpleasant news for the Grammar Instructor, but then he plucks the memory of their interaction from her mind, slips into a secret opening constructed while sampling a student’s confiscated coca leaf collection. And what does he find in the secret passageway? And what does he do to the poor unfortunate? And what will Gundrun do when they meet again moments after that other meeting she has now has no recollection of?