Harry locates the One Eyed Witch using the Maurauder's Map.

A spell used to reveal a secret passage


Dissendium fact file


Purpose

Opens the secret passageway concealed in the statue of Gunhilda of Gorsemoor

Famous moment a wizard or witch uses it

Harry, Fred, George and the Marauders have all used this spell to gain access to the secret passageway from Hogwarts to the cellar in Honeydukes