Duelling practice

Students lined the walls of the Room of Requirement, waiting patiently as Ginny stood, trying to remember any duelling spells at all. Ten feet away stood Hermione Granger, tapping her foot impatiently.

"See, this won't do." Hermione suddenly announced, "If the minions of You-Know-Who storm the school, they won't wait because you've forgotten how the spells go."

"Sorry," Ginny replied nervously, "I haven't had much experience."

"Then you'll have to learn. Defend against this." Hermione flicked her wand, "Garmentus Gone!"

Ginny felt a sudden tugging at her uniform from all sides, as if invisible hands all around her were grabbing it. Then there was a sudden popping noise, buttons went flying and stitches tore. She was horrified to see her blouse go flying off in one direction, her skirt another. She couldn't possibly grab them both.