Does fire have a shape in space?

Demon fire

A Demon fire (in the original: Fiendfyre) is an extremely difficult to control fire created by a black magic curse, the flames of which take the form of a wide variety of shapes. What they capture and burn cannot be magically repaired. Therefore, demon fire is one of the few powerful things with the power to destroy horcruxes. However, it is extremely dangerous to start such a devastating fire, because it cannot be extinguished with water or with common fire-extinguishing spells.

Event in the book Harry Potter and the Deathly Hallows

  • This spell is usually not taught at Hogwarts. During the 1997/98 school year, however, the new subject teacher Amycus Carrow may have taken it through in the senior class when he taught black magic applications in his classes instead of Defense Against the Dark Arts.
  • In any case, Vincent Crabbe is able to conjure up a demon fire, but then cannot control it, so that he perishes in it. It is not clear whether Draco Malfoy or Gregory Goyle could have put out the fire, as both lost their wands beforehand.
  • The demon fire created by Crabbe takes on the form of flaming beasts that pursue and destroy everyone and everything that is at the place of fire, the room of wishes. An object made into a Horcrux that is hidden in this room will be irreparably destroyed, as will everything else that is stored there.
  • The demon fire is limited to the magical room, which has just taken the shape of the spacious hall for hiding objects of all kinds. The fire does not spread to other rooms in the castle. Ron wonders if the magical room of desires will still work after the fire. His question is not answered (HP VII / 31).