It couldn't have been more perfect, the prat actually rolled away from her and looked the other way.
She laid there for a moment and pondered if she could really do this, could she really make Draco totally forget that they had been shagging like rabbits all week? It would never happen again, she doubted they would ever both be in the position of having detention together or alone in any sort of way. She laid there with her eyes closed and realized that she had to do it or eventually, this would get out and it would destroy them both.
She waited several moments, listening to his breathing, waiting for him to relax into a state of calm. As gently as she could, Hermione moved her wand out from behind where she had tucked against her side and pointed it at Draco's back. Having mastered non-verbal spells early in the semester, Hermione cast "Stupify" to insure he was instantly out cold.