Harry Potter and the Half-Blood Prince
Hermione had managed to squeeze through to a large display near the counter and was reading the information on the back of a box bearing a highly colored picture of a handsome youth and a swooning girl who were standing on the deck of a pirate ship.
"One simple incantation and you will enter a top-quality, highly realistic, thirty-minute daydream, easy to fit into the average school lesson and virtually undetectable (side effects include vacant expression and minor drooling." (6.95-96)
"That's right….Well, we thought Shield Hats were a bit of a laugh, you know, challenge your mate to jinx you while wearing it and watch his face when the jinx just bounces off. But the Ministry bought five hundred for all its support staff! And we're still getting massive orders!" (6.112)
"The Dark Arts," said Snape, "are many, varied, ever-changing, and eternal. Fighting them is like fighting a many-headed monster, which, each time a neck is severed, sprouts a head even fiercer and cleverer than before. You are fighting that which is unfixed, mutating, indestructible." (9.55)