“Of the many fearsome beasts and monsters that roam our land, there is none more curious and more deadly than the Basilisk, known also as the King of Serpents. This snake, which may reach a gigantic size, and live many hundreds of years, is born from a chicken’s egg, hatched beneath a toad.“
“Its methods of killing are most wondrous’ for aside from its deadly and venomous fangs, the Basilisk has a murderous stare, and all who are fixed with the beam of its eye shall suffer instant death. Spiders flee before the Basilisk, for it is their mortal enemy, and the Basilisk flees only from
the crowning of the rooster, which is fatal to it.”
Before the start of Ginny Weasley’s first year at Hogwarts, Lucius Malfoy slipped Tom Riddle’s diary in her books. When Ginny discovered the diary, she began writing in it and was soon possessed by Lord Voldemort. She opened the fabled Chamber of Secrets which was believed to be a myth by the wizards of Britain. By opening the Chamber, she released the Basilisk for the second time. Looking directly into the Basilisk’s eyes can kill a person instantly.
When it was loose on the premises of Hogwarts, it petrified four students, a ghost, and a cat. They didn’t die because no one looked the Basilisk directly in the eye, they all had a medium through which they looked at the Basilisk indirectly (the ghost of Sir Nicholas did look at the Basilisk directly but he was already dead and couldn’t die twice). When Harry Potter gets hold of the diary and uses it to gather information about the Chamber and the “horror” associated with it.
By that time, Tom Riddle had abducted Ginny and placed her inside the Chamber. With the help of a piece of paper he found in petrified Hermione’s hands, he and Ron conclude that the student who died when the Chamber was opened for the first time, was none other than Moaning Myrtle, and the horror inside the Chamber is called a Basilisk.
Who placed Basilisk in Chamber of Secrets?
Basilisk was a creature placed in the Chamber by Salazar Slytherin, one of the founders of Hogwarts, with the original intent to kill the Muggle-born students. With Myrtle’s help, they find the entrance to the Chamber. Inside the Chamber, Harry Potter found an unconscious Ginny, a memory of Tom Riddle preserved by the diary getting stronger by the second and the Basilisk.
Harry, aware of the Basilisk’s capabilities, simply runs away from it as he had no plan to fight a creature that can kill him just by making eye contact. Fortunately, Fawkes the Phoenix intervenes and claws its eyes out destroying his lethal gaze. But the Basilisk still was a powerful gigantic serpent and still had its venomous fangs.
Harry, gaining enough confidence to fight back, retrieves the Sword of Gryffindor from the Sorting hat. After fighting with the Basilisk for a while, Harry is able to stab it through the roof of its mouth, killing the beast. But while doing this, one of its fangs pierced Harry’s arm.
Harry could have died because of the venom but Fawkes appeared at the right moment and shed his tears on Harry’s wound. Phoenix tears have healing abilities and can heal any wound and Harry was saved.
Why Basilisk’s venom didn’t destroy the Horcrux inside Harry
Harry uses the same fang to destroy Tom Riddle’s diary, killing the memory preserved in it. Later on, we discover that the diary was a Horcrux, an object which preserved a part of Voldemort’s soul, and by destroying the diary, Harry also destroyed the Horcrux inside it.
Years later, when Harry, Ron, and Hermione went on a quest to find and destroy Voldemort’s Horcruxes, they used the sword of Gryffindor to destroy several other Horcruxes. They concluded that the Basilisk’s venom had the capability of destroying the Horcruxes and when Harry stabbed the Basilisk with the Sword, it was imbued with the venom and could be used to destroy the Horcruxes.
This is where the fans get confused. If Basilisk’s venom is so powerful, that its fangs can be used to destroy an object as powerful as a Horcrux, years after the beast’s death, and the sword that once stabbed the Basilisk also fulfills the same purpose, then why didn’t the Basilisk’s venom destroy the Horcrux inside harry when the fang pierced his arm?
The answer is, that in order for a Horcrux to be destroyed, the object that preserves it needs to be completely destroyed beyond repair. Every other Horcrux was destroyed because the objects holding them were also destroyed. But when Harry’s arm was pierced, he was saved, and with him, the Horcrux inside him was saved too.