“It’s nothing, Molly,” mumbled Mr. Weasley, “Fred and George just—but I’ve had words with them—”

“What have they done this time?” said Mrs. Weasley. “If it’s got anything to do with Weasleys’ Wizard Wheezes—”

“Why don’t you show Harry where he’s sleeping, Ron?” said Hermione from the doorway.

“He knows where he’s sleeping,” said Ron, “in my room, he slept there last—”

“We can all go,” said Hermione pointedly.

“Oh,” said Ron, cottoning on. “Right.”

“Yeah, we’ll come too,” said George.

“You stay where you are!” snarled Mrs. Weasley.

Harry and Ron edged out of the kitchen, and they, Hermione, and Ginny set off along the narrow hallway and up the rickety staircase that zigzagged through the house to the upper stories.

“What are Weasleys’ Wizard Wheezes?” Harry asked as they climbed.

Ron and Ginny both laughed, although Hermione didn’t.

“Mum found this stack of order forms when she was cleaning Fred and George’s room,” said Ron quietly. “Great long price lists for stuff they’ve invented. Joke stuff, you know. Fake wands and trick sweets, loads of stuff. It was brilliant, I never knew they’d been inventing all that . . . ”

“We’ve been hearing explosions out of their room for ages, but we never thought they were actually making things,” said Ginny. “We thought they just liked the noise.”

“Only, most of the stuff—well, all of it, really—was a bit dangerous,” said Ron, “and, you know, they were planning to sell it at Hogwarts to make some money, and Mum went mad at them. Told them they weren’t allowed to make any more of it, and burned all the order forms . . . She’s furious at them anyway. They didn’t get as many O.W.L. s as she expected.”

O.W.L. s were Ordinary Wizarding Levels, the examinations Hogwarts students took at the age of fifteen.

“And then there was this big row,” Ginny said, “because Mum wants them to go into the Ministry of Magic like Dad, and they told her all they want to do is open a joke shop.”

Just then a door on the second landing opened, and a face poked out wearing horn-rimmed glasses and a very annoyed expression.

“Hi, Percy,” said Harry.

“Oh hello, Harry,” said Percy. “I was wondering who was making all the noise. I’m trying to work in here, you know—I’ve got a report to finish for the office—and it’s rather difficult to concentrate when people keep thundering up and down the stairs.”

“We’re not thundering,” said Ron irritably. “We’re walking. Sorry if we’ve disturbed the top-secret workings of the Ministry of Magic.”

“What are you working on?” said Harry.

“A report for the Department of International Magical Cooperation,” said Percy smugly. “We’re trying to standardize cauldron thickness. Some of these foreign imports are just a shade too thin—leakages have been increasing at a rate of almost three percent a year—”

“That’ll change the world, that report will,” said Ron. “Front page of the Daily Prophet, I expect, cauldron leaks.”