He feels a twinge of exasperation - he'd forgotten, caught up in the moment as he was, that he's dealing with a true simpleton. Worse than Crabbe and Goyle, in that way. But Crabbe and Goyle aren't here, and inconvenient times call for inconvenient measures.

"It's a special wizard contract," he explains loftily. "Just spit into your hand and hold it out, and let me do the talking." She does so, to his satisfaction, and Draco gives her hand a squelchy clasp and adopts an even more pompous tone. "I promise not to ask you to steal any faces, provided you are otherwise obedient to my commands."

He lets his voice lapse back into a more normal register and explains, "Now you promise to obey my orders so long as they don't involve face stealing, and we'll have a bargain."