One-Eyed Witch Spell

Warning!

At least some content in this article is derived from information featured in: Harry Potter: Puzzles & Spells & Harry Potter: Magic Awakened & Hogwarts Legacy.
As such, spoilers will be present within the article.

"At once, the statue's hump opened wide enough to admit a fairly thin person."

— Description^[src]

The One-Eyed Witch Spell^[3] (Dissendium)^[2] was a charm used to open the One-Eyed Witch Passage in the third corridor at Hogwarts castle.^[2] The incantation Dissendium could be used to open secret passageways in general.^[1]

Known practitioners[]

While initially this appears to be a simple password for the statue, it was used in Harry Potter and the Deathly Hallows: Part 1 in an attempt to destroy Slytherin's Locket.
It is unknown what may happen if Dissendium is used on something else besides passageways; for example it caused a small explosion when it was used in a failed attempt to destroy the locket.^[8]

↑ ^1.0 ^1.1 ^1.2 Pottermore
↑ ^2.0 ^2.1 ^2.2 ^2.3 ^2.4 ^2.5 Harry Potter and the Prisoner of Azkaban, Chapter 14 (Snape's Grudge)
↑ Wizarding World - A guide to the lesser known spells in the wizarding world
↑ ^4.0 ^4.1 Hogwarts Legacy, Side Quest "'Dissending' for Sweets"
↑ ^5.0 ^5.1 Seeing how he knew of the passage and where it led, it is more than likely he used it. And as one had to perform this spell to use it, he thus used the spell.
↑ Hermione retrieved Harry's cloak from beneath the One-Eyed Witch; she needed to have cast Dissendium to open the passage.
↑ Harry Potter: Magic Awakened
↑ Harry Potter and the Deathly Hallows: Part 1