Lumos: the wand-lighting charm

Lumos makes the tip of a spellcaster’s wand shine. It is a practical charm for seeing in dark places, including the Forbidden Forest. Its counter-spell is Nox, which extinguishes the wand-light. 1 2

The official Nox fact file notes one canon use: Harry and Hermione extinguish their wands as they approach the Shrieking Shack. 2

A small charm, but a revealing one: in the wizarding world, knowing when to make light—and when to remove it—can both get you where you are going.