Tom Riddle: "Stand aside, Hagrid!"
Rubeus Hagrid: "No!"
Tom Riddle: "Cistem aperio!"
— Riddle's use of the spell in 1943[src]

Cistem Aperio is the incantation of a charm that is used to blast open a trunk, chest, box or crate with a burst of white light[1].

Being more specific than other opening spells in that it works only on trunks, chests, boxes or crates, may increase the spell's potency against a warded target of the appropriate kind[1].


Tom Riddle used this spell to blast open the chest in which Aragog, the pet-acromantula of Rubeus Hagrid, lived in during its time at Hogwarts Castle[1].

During the 1987–1988 school year, Professor Filius Flitwick taught this charm to Jacob's sibling and classmates.[2]


Aperio is Latin for open, uncover, lay bare, reveal, or make clear. Cistem is a corruption of cistam, a form of the Latin word for 'box' or 'basket'.

Behind the scenes

Severus spell

Severus Snape possibly casting the spell


Notes and references

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Harry Potter and the Chamber of Secrets (film) (Chapter Twenty-Three - Tom Riddle)
  2. Harry Potter: Hogwarts Mystery, Year 4, Chapter 7 (Beast, Beings, and Creatures)