"You can't eat in the library," she insisted in an urgent whisper. "You'll leave crumbs and drop things."
"Someone'll be along to pick them up," Draco shrugged over his admittedly crumbly cookies. "You really don't want any?"
But the Gryffindor, having latched onto the issue, was not to be distracted. "Who, exactly, is going to clean up after you, Malfoy?"
"Well, house elves obviously... oh, no," he finished in genuine dismay at her expression.
"House elves."
"With everything you read, you've never heard of house elves," Draco complained. He felt it entirely beneath him to notice the creatures except when strictly necessary; let alone having to explain them to mudbloods and...well, Potter. "They live in houses and do the cooking and cleaning... whatever needs doing. Hogwarts has lots. Stop worrying about the crumbs."
"Why?"
"Like I said - it'll get cleaned up. Keep your voice down, will you?"
"I meant why do they do the cleaning up?"
Draco slouched lower, certain that getting the shrill girl's help, and perhaps Arithmancy answers, was not worth the humiliation of sitting in the library, whispering about the servants. "Orders. House elves're bound to obey, no matter what. It's simpler than broomsticks, Granger -"
"They're slaves, you mean." Draco was leaning over, pulling out the book she'd asked for last week, and missed seeing her expression of horror.
"They're house elves, Granger," he drawled. "Don't get romantic, and keep your voice down."
"It isn't right to keep another intelligent being in bondage."
She got like this in classes, sometimes: so attached to a thought that not even the professor could get her off it. "Shows you've never talked to a house elf. Granger, they'll iron their own hands if you tell them to - they aren't smart."
"If it's magical slavery, it's even worse. Isn't Imperius illegal?"
"It's not Imperius - they're not even people. Look, Granger." He propped his feet on her table, leaned back precariously. "If I'm to have an ugly little creature that isn't so bright, or so nice, and can do magic without wands running about my house, it had better bow and cringe and call me 'master'."
The mudblood girl shook her head vigorously, upsetting whatever order it was she tried to impose on her hair. "That just means the entire system's wrong."
"Works fine for me," Draco confirmed. "Are you done yet?"
"For now," Granger said, opening her Arithmancy texts.