This storeroom was where Severus Snape stored his private supply of potions and potion ingredients in Hogwarts. These included Veritaserum and ingredients for Polyjuice Potion. It was broken into on at least two occasions, the first during the 1992-1993 school year, when Hermione Granger stole several of the ingredients required in the brewing of Polyjuice Potion. It was again broken into, during the 1994-1995 school year, when Bartemius Crouch Jr. stole ingredients for Polyjuice Potion, which he was using to disguise himself as Alastor Moody. Snape suspected Harry Potter of stealing the ingredients until Crouch was interrogated at the end of the school year.
- Harry Potter and the Goblet of Fire (First mentioned)
- Harry Potter and the Goblet of Fire (film) (First appearance)
- Harry Potter and the Chamber of Secrets (video game)