======Diary of Tom Riddle======
=====Object Information=====
  * **Type:** [[Horcrux]], [[Dark Artefact]], [[Diary]]
  * **Owners:** [[Tom Marvolo Riddle]], [[Lucius Malfoy]], [[Ginny Weasley]], [[Harry Potter]]
  * **Maker:** [[Tom Marvolo Riddle]]
=====Description and Appearance=====
The diary of [[Tom Riddle]] was a small, thin book with a black leather cover. It was purchased by a young [[Tom Riddle]] from a [[Muggle]] newsagent's shop on [[Vauxhall Road]] in [[London]]. Stamped on the front in faded gold lettering was the year "1943".
Internally, the diary's pages were completely blank and did not respond to being written on with ordinary ink. When a user wrote on a page with a quill, the ink would shine for a moment and then vanish as if absorbed into the paper, prompting a written response from the enchanted memory of [[Tom Riddle]] stored within.
=====Magical Properties and Usage=====
As [[Voldemort]]'s first [[Horcrux]], the diary contained a fragment of his sixteen-year-old soul. Its primary purpose was to preserve that soul fragment, tethering [[Voldemort]] to life. However, it was also enchanted with powerful and insidious [[Dark Magic]] to act as a weapon.
  * **Two-Way Communication:** The diary functioned as a means of communication. Anyone writing in it would receive replies from the sentient memory of [[Tom Riddle]]. This memory was designed to be charming and sympathetic, preying on the writer's deepest fears and secrets to earn their trust.
  * **Possession and Manipulation:** The diary's most dangerous ability was its power to possess the writer. By feeding on the emotions and secrets confided to it, the soul fragment within grew stronger, eventually gaining enough influence to control the writer's body. Through this method, it forced [[Ginny Weasley]] to open the [[Chamber of Secrets]] and unleash the [[Basilisk]] upon [[Hogwarts]].
  * **Memory Projection:** The diary could pull a reader into a recreation of one of [[Tom Riddle]]'s memories. It used this power on [[Harry Potter]], showing him a manipulated version of events where [[Riddle]] appeared to be a hero who had caught [[Rubeus Hagrid]] opening the [[Chamber of Secrets]].
  * **Life-Force Absorption:** The diary's ultimate goal was to drain enough of the life force from its victim to allow the memory of [[Tom Riddle]] to become fully corporeal and independent, effectively resurrecting the sixteen-year-old [[Voldemort]] at the cost of the victim's life. It nearly succeeded in this with [[Ginny Weasley]].
=====History=====
In 1943, during his fifth year at [[Hogwarts]], [[Tom Riddle]] used the [[Basilisk]] to murder a fellow student, [[Myrtle Warren]], in a girls' bathroom. He used this murder to perform the complex [[Dark Magic]] required to split his soul and create his first [[Horcrux]], embedding a fragment of his soul into the diary.
Years later, before his first fall from power, [[Lord Voldemort]] entrusted the diary to his loyal [[Death Eater]], [[Lucius Malfoy]], for safekeeping. He instructed [[Malfoy]] to ensure the diary was one day smuggled back into [[Hogwarts]] to reopen the [[Chamber of Secrets]], though he did not reveal its true nature as a [[Horcrux]].
In the summer of 1992, during a confrontation at [[Flourish and Blotts]], [[Lucius Malfoy]] slipped the diary into [[Ginny Weasley]]'s cauldron among her secondhand schoolbooks. Over the following school year, [[Ginny]] confided in the diary and became possessed by [[Riddle]]'s memory. Under its influence, she unleashed the [[Basilisk]], which petrified several students. Frightened, [[Ginny]] attempted to dispose of the diary by flushing it down a toilet in what was now [[Moaning Myrtle]]'s bathroom.
[[Harry Potter]] later found the diary. After he communicated with it and was shown the false memory, [[Ginny]] stole it back, fearing [[Harry]] would discover her role in the attacks. The diary then forced her into the [[Chamber of Secrets]] to complete its plan of resurrection. [[Harry]] followed and, with help from [[Fawkes]] the [[phoenix]] and the [[Sword of Godric Gryffindor]], slew the [[Basilisk]]. He then used a broken [[Basilisk fang]] to stab the diary, destroying the [[Horcrux]] within it. The highly corrosive [[Basilisk venom]] is one of the few substances capable of destroying a [[Horcrux]].
=====Role in the Story=====
The diary is the central mystery and antagonistic force in //Harry Potter and the Chamber of Secrets//. Its discovery and eventual destruction by [[Harry Potter]] provides the first major clue to [[Voldemort]]'s past and the nature of his immortality. It represents [[Harry]]'s first direct confrontation with a piece of [[Voldemort]]'s soul.
In //Harry Potter and the Half-Blood Prince//, [[Albus Dumbledore]] reveals the diary's true nature as a [[Horcrux]] to [[Harry]]. This revelation reframes [[Harry]]'s past victory as a critical, if then unknown, step towards defeating [[Voldemort]]. The diary serves as the primary example that helps [[Harry]] understand the [[Horcrux]] concept, setting him on the path to hunt and destroy the remaining ones.
=====Behind the Scenes=====
  * J.K. Rowling stated that the idea of a diary being able to "write back" was a frightening concept she had as a child, and that a diary was a very fitting [[Horcrux]] for a narcissistic teenager, as it is a repository for secret, powerful thoughts (Pottermore).
  * In the film adaptation of //Harry Potter and the Chamber of Secrets//, the diary's destruction is depicted with a torrent of black, ink-like blood pouring from the puncture wounds, and the ghostly form of [[Tom Riddle]] screaming and exploding into light as the [[Horcrux]] is destroyed (film).