Luna first found out about the enchanted bookshelves in her first year. She was walking to Transfiguration when a burly second-year tripped her in the hall. She sprawled on her face as the onlookers snickered. A pretty third-year Ravenclaw, Cho Chang, helped her up.
"Thanks," Luna muttered. "Where's my book?" She looked around, and spotted A Standard Book Of Spells, Grade One in the hand of Draco Malfoy, a slight, blond-haired Slytherin second-year. He was holding Luna's book with a smirk on his face that Luna didn't like. She was considering opening her mouth to tell him to give her back her book, but Cho beat her to it.
"Give that back," she demanded of Malfoy, who appeared to consider her demand with his cronies, Crabbe and Goyle.
"Y'know what," he said, "I don't think I will." He tossed the book to Goyle, who threw it on the floor hard. It landed, a crumpled mess. Luna walked over to pick it up, and as she took hold of it, a bunch of pages fluttered out and landed on the floor. She sniffled.
"Here, I'll help you." It was Cho again.
"But, how? The library's all the way on the other side of the school and I don't even know if they've got an extra copy and I'll be late for class and McGonagall's going to kill me!"
"Shhh." Cho took Luna back to the spiral staircase and up to the common room.
"What is the incantation to turn matches into needles?" the door knocker asked.
"Figures," sniffed Luna. "That's what we're learning today."
Cho wasn't paying attention. "Acifors."
"Correct." The door swung open.
Cho took Luna to one of the large bookshelves. "They're enchanted," she explained. "Summons the book you need from the library. But be careful to enunciate clearly. I once asked for Beginner's Potions and got Bloodcurdling Poisons. Flitwick wasn't happy. And after that they stopped students being allowed to summon books from the Restricted Section."
"Thank you so much!" Luna said. "A Standard Book Of Spells, Grade One." A space opened in the bookshelf, and the book appeared. She took it out. It was spotless.
"It should do," Cho said. "I'll try to fix your copy up later."
"Thank you, Cho."
"No problem. Come to think of it, though, I've got Potions now, and I'm about ten minutes late... See you later!"