She rushed back to the fireplace and flooed to The Leaky Cauldron, where she made the quick walk to Flourish and Blotts. The witch behind the counter made it clear she did not want to get too close, but helped Hermione find as many books on the middle ages she could carry. She had no idea how long this potion would last, and did not want to be in the middle of Diagon Alley when it wore off. 