The Vanishing Cabinet of Hogwarts was a large, dark cupboard located in a first-floor corridor of the castle. In Harry Potter's second year, it was described as being black-and-gold. It is one of a pair of identical cabinets that form a secret magical passageway; an object or person entering one cabinet will instantly emerge from the other. Its twin was located in Borgin and Burkes, a shop specializing in the Dark Arts on Knockturn Alley. The cabinet's history at the school is not fully detailed, but by the 1992-1993 school year, it was known to be broken. During an incident where Harry Potter was caught dripping mud in the corridor by Argus Filch, Nearly Headless Nick persuaded the poltergeist Peeves to create a diversion. Peeves did so by dropping the Vanishing Cabinet from a great height, smashing it directly above Filch's office. In the 1995-1996 school year, Fred and George Weasley shoved Graham Montague, a Slytherin student and member of the Inquisitorial Squad, into the broken cabinet. Montague was trapped in a state of limbo between Hogwarts and Borgin and Burkes, eventually managing to escape by Apparition. The experience was deeply traumatic but provided Draco Malfoy with the critical knowledge that the cabinet linked the two locations.
The Vanishing Cabinet played a pivotal role in the events leading to the Second Wizarding War's escalation within Hogwarts. Tasked by Lord Voldemort with a mission to kill Albus Dumbledore, Draco Malfoy realized that the cabinet could be used to bypass the castle's formidable protective enchantments. Throughout the 1996-1997 school year, Malfoy used the Room of Requirement as a workshop to repair the damaged cabinet. He conducted several tests to check his progress, including sending in an apple and a small bird, both of which showed signs of having successfully made the journey to Borgin and Burkes. Malfoy ultimately succeeded in mending the cabinet. He used it to create a passage for a group of Death Eaters, including Bellatrix Lestrange and Fenrir Greyback, to secretly infiltrate Hogwarts. This invasion led directly to the Battle of the Astronomy Tower, during which Albus Dumbledore was disarmed by Malfoy and killed by Severus Snape. The Vanishing Cabinet thus served as the critical tool that allowed Voldemort's forces to breach the school's defenses and assassinate its Headmaster.