Excuse me?

"This is the most complicated potion I've ever seen," said Hermione as
they scanned the recipe. "Lacewing flies, leeches, fluxweed, and
knotgrass," she murmured, running her finger down the list of
ingredients. "Well, they're easy enough, they're in the student store-
cupboard, we can help ourselves ... Oooh, look, powdered horn of a
Bicorn - don't know where we're going to get that - shredded skin of a
Boomslang -. that'll be tricky, too and of course a bit of whoever we
want to change into."

"Excuse me?" said Ron sharply. "What d'you mean, a bit of whoever
we're changing into? I'm drinking nothing with Crabbe's toenails in it -"

Hermione continued as though she hadn't heard him.

"We don't have to worry about that yet, though, because we add those
bits last ...

Ron turned, speechless, to Harry, who had another worry.

"D'you realize how much we're going to have to steal, Hermione?
Shredded skin of a boomslang, that's definitely not in the students'
cupboard. What're we going to do, break into Snape's private stores? I
don't know if this is a good idea ..."

Hermione shut the book with a snap.

"Well, if you two are going to chicken out, fine," she said. There were
bright pink patches on her cheeks and her eyes were brighter than
usual. "I don't want to break rules, you know. I think threatening
Muggle-borns is far worse than brewing up a difficult potion. But if
you don't want to find out if it's Malfoy, I'll go straight to Madam Pince
now and hand the book back in -'

"I never thought Id see the day when you'd be persuading us to
break rules," said Ron. "All right, we'll do it. But not toenails, okay?"