Counter-enchantment

Counter-enchantment
Type	Charm
Effect	Prevents bewitchment from another charm

Ron Weasley: "Is that it, then? It’s not here?"

Hermione Granger: "Oh, it could still be here, but under counter-enchantments. Charms to prevent it from being summoned magically, you know."

Harry Potter: "Like Voldemort put on the stone basin in the cave."

— Hermione Granger failing to summon Slytherin's Locket in 12 Grimmauld Place

A Counter-enchantment was a type of charm placed on an object, to prevent it being bewitched by another charm.

History

Regulus Black placed a counter-enchantment on the fake Slytherin's Locket in Tom Riddle's cave, without his former master knowing he had Kreacher steal the real Horcrux. As a result, Harry Potter was unable to summon the fake locket in 1997 with the Summoning Charm, when he and Albus Dumbledore infiltrated the cave to take the Horcrux.

Later in 1997, Hermione Granger used the Summoning Charm in an attempt to summon the real locket at 12 Grimmauld Place. When she failed to summon anything, she told Harry Potter and Ron Weasley that a counter-enchantment may have been placed on it to prevent it being summoned magically, where in reality the locket had been stolen from the property beforehand by Mundungus Fletcher.

Appearances

• Harry Potter and the Half-Blood Prince (First appearance)
• Harry Potter and the Deathly Hallows (First identified as Counter-enchantment) (Mentioned only)