Ousting of Severus Snape

This duel started as Severus Snape decided to attack Harry Potter just before the Battle of Hogwarts. Minerva McGonagall, Pomona Sprout, and Filius Flitwick defended Harry by duelling Snape.

Duel
The three professors fought the Headmaster until he fleed at the arrival of Professors Sprout and Flitwick.

Differences In the Movie

 * The duel takes place in the Great Hall
 * Sprout and Flitwick do not help McGonagall
 * McGonagall uses one spell repeatedly
 * Snape casts his Shield Charms, defeating Amycus and Alecto Carrow in the process
 * Snape disapparated and crashed through the window
 * After Snape left, McGonagall called him a coward