Their first stop was at Zonko’s in the hopes that Seamus and Dean wouldn’t have made it out of the castle quite so early in the day.  (They hadn’t.)  Happily, Ron and Harry moved about the shop making hushed whispered plans.  Every so often they’d turn to Hermione with a question about a spell, which she would gladly provide, but otherwise she tuned them out.  She’d found it was safer if she didn’t know what exactly their prank entailed when it involved Seamus.  The retaliation was never worth her involvement.