Tom Riddle

Through his diary Riddle tells Harry that he was a student at Hogwarts the last time the Chamber of Secrets was opened. He also shows Harry his memory of the night he caught Hagrid, whom he accused of being behind the attacks. In the memory Riddle is a tall, sixteen-year-old boy with jet-black hair not unlike Harry's.

Riddle orders the Basilisk to kill Harry, speaking to it in Parseltongue.

Riddle thinks that the venom from the Basilisk fang in Harry's arm will kill him, but Harry is cured by Fawkes' tears. Harry uses the Basilisk fang to pierce Riddle's diary, causing ink to spurt out of it in torrents. After writhing, twisting, screaming and flailing in agony, Riddle vanishes.

At eleven, Tom is a miniature of his handsome father; tall for his age, dark-haired and pale. He is sitting on the bed in his room when Dumbledore enters with Mrs Cole. Initially wary of the teacher, Tom suspects that he is, in fact, a doctor. He orders Dumbledore to tell the truth, speaking the command with a ringing force that is almost shocking. He believes Dumbledore is taking him to live in an asylum, and furiously protests that he is not mad. Tom freezes when Dumbledore explains that Hogwarts is a school of magic, and flushes with excitement when he realises he is a wizard. He tells Dumbledore that he can make things move without touching them, can make animals do what he wants with no training, and that he can make people hurt. He claims he always knew he was special, and is transformed with a wild happiness, his expression almost bestial.

Tom tells Dumbledore to prove that he is a wizard as well. He is shocked and howls with rage when Dumbledore points his wand at Tom's wardrobe, causing it to burst into flames. He stares at the professor when the flames vanish and the wardrobe stands undamaged once again. Tom is frightened when a rattling is heard from the wardrobe, and reluctantly fetches a small cardboard box from the wardrobe, which is shaking and rattling with force. He tips the contents of the box on to the bed at Dumbledore's request, revealing a mess of objects, including a yo-yo, a silver thimble and a tarnished mouth-organ. He is ordered to return the objects to their rightful owners by Dumbledore, and agrees to do so, staring coldly and appraisingly at the teacher.

Tom is told of a fund at Hogwarts to help those who require assistance to buy spellbooks and robes. He is eager to visit Diagon Alley on his own, reluctant to have Dumbledore's escort; he is handed an envelope containing his list of required equipment and is given the directions to the Leaky Cauldron. Riddle gives an irritable twitch when Dumbledore mentions that the barman of the pub shares his name, Tom, disliking the idea of having such a common name. As he and Dumbledore shake hands, Tom reveals that he can speak to snakes, and that the creatures often find him and whisper to him when he is on country trips.

Tom's eyes flash scarlet when Hepzibah shows him her second treasure, Slytherin's locket, and explains that it was sold to Caractacus Burke by a ragged-looking woman. Tom is aware that the woman was his mother, Merope Gaunt.

Professor Dumbledore suspects that Tom was responsible for the death of Hepzibah Smith, and the theft of both the items afterwards. He believes Tom modified the memory of Hokey the house-elf to frame her for the murder, much as he did with Morfin Gaunt. By the time Hepzibah's family realised Hufflepuff's cup and Slytherin's locket were missing, Tom had resigned from Borgin and Burkes and disappeared. Dumbledore believes that Tom saw the locket as rightfully belonging to him, as he was descended from the Hogwarts founder, and could not resist possessing it.