"AUTHOR, Mary-Sue Is-the," called out Professor McGonagall. The stunning beautiful/mysterious-in-a-sexy-way/strangely captivating/totally contrived girl bounded up to the Sorting Hat and plumped it down eagerly on her head. The hat recoiled.
"Oh, bloody hell, not another one," it said inside Mary-Sue's head. She frowned prettily.
"I don't understand," she thought back. The hat heaved what sounded suspiciously like a martyred sigh.
"I get one of you every year. The stunning beautiful/mysterious-in-a-sexy-way/strangely captivating/totally contrived exchange student from America."
"Have you been stalking me?!"
"What? I'm a hat!!"
"Oh… right."
"As I was saying… you seem suspiciously like…a MARY-SUE!" proclaimed the hat, yelling the last words out to the hall. There was a hushed silence, followed by a sudden explosion of noise. Doors slammed shut and locked, alarms wailed, the lights went out (just for dramatic tension) and some HAZ-MAT clad wizards burst into the hall through the enchanted ceiling. Mary-Sue looked around, mildly alarmed.
"There it is!" yelled one, his outstretched arm pointing straight at Mary-Sue.
"Get it!" screamed another in an entirely overenthusiastic way.
The HAZ-MAT wizards pounded through the hall, knocking over tables and sending students flying. They seized Mary-Sue by the arms and began to drag her from the hall.
Applause flooded the hall as Mary-Sue's fingernails were pried from the doorjamb and she disappeared off into the night.