Im having the same problem, you can "get past" it by completing the quest with console commands (setstage dlc2mq05 1000), but you have to add the final word in yourself (player.teachword xx0179db) as well, and frea and storn end up permanently stuck in the same spot with the same dialogue, like they're still waiting for the quest to finish. I havent found a way to get the quest going by itself yet, but Im still trying. I have a feeling storn is missing a script or something that sets off him reading the book, and I wouldnt really have any idea how to fix it if it requires going beyond console commands
