仕込み
1ハリー・ポッターと賢者の石 · The first Quidditch match
Harry’s broom bucks. Hermione sees Snape staring at him and muttering, and she sets fire to Snape’s robes to break his concentration.
The scene is staged so the obvious suspect is the teacher who already dislikes Harry.
回収
ハリー・ポッターと賢者の石 · After the traps under the school
Quirrell tells Harry that he himself was jinxing the broom, and that Snape’s muttering was a counter-curse. Snape’s refereeing and his glares were cover for protecting the Stone, not for helping Voldemort.
