Chapter 11: Only Hermione Realised The Monster Was A Basilisk
Context: The History of Magic class in which Binns speaks about the Chamber has just finished.
As the second years left the classroom, Harry was deep in thought. "I've got an idea!" he said. "Instead of trying to find out where the Chamber is, why don't we try to work out what Slytherin's monster is?" "What good would that do, though?" asked Ron. "Even if we worked out what it is, we still wouldn't know where it is." "But if you knew what the monster was, you could work out where it isn't, or where it couldn't be – or maybe even how to kill it." As one, Harry, Hermione and Ron hurried for the library, their dinner forgotten. This was important.
"There are two points we need to focus on," Hermione said as they ran. "Slytherin himself, and creatures that petrify you. Mrs Norris wasn't injured, so she wasn't bitten or scratched, so it has to be caused some other way." Suddenly, Ron stopped dead in his tracks. Harry and Hermione turned to see him standing in the middle of the corridor with wide eyes and giving an impression he was ready to run; looking at a line of spiders moving along the floor as fast as they could, up to a silken thread which Harry traced up to an open window. "That's strange," Hermione said. "I've never seen spiders act like that." Ron was still fixated on the spiders. "I-don't-like-spiders." he said. "I never knew that," said Hermione. "You've used them in potions loads of times." "I don't mind them dead, I just don't like the way they move." Hermione giggled. "You wouldn't like them either," he said as they carried on down the corridor, "if your brother turned your teddy bear into one when you were three because you accidentally broke his toy broomstick."
When they got to the library, Ron began pulling all the bestiaries he could find off the shelves. Harry started on a copy of Fantastic Beasts and Where To Find Them, while Hermione grabbed A Biographic Record of the Founders of Hogwarts. "The Slytherin emblem is a snake," he said, so I reckon the monster must be one." He started scanning the entries. "Ashwinder – Is a snake, but doesn't petrify, and the castle would have burned down centuries ago, because they only live for an hour, and the eggs burn down houses in minutes if you don't manage to find and freeze them, so not that. Runespoor – Is a snake, but it's only six feet long. They don't live very long, because they have three heads and tend to attack each other."
Ron looked up from the book he was checking. "Cockatrices petrify you," he reported. "Wait.. hang on.. Oh. It happens if you get scratched with their beaks, and it only lasts for a day." He turned the book around, to show Harry a picture of something that looked like an extremely ugly and scaly chicken with leathery, bat-like wings.
Hermione slammed A Biographic Record shut and announced that the only relevant information about Salazar Slytherin and snakes was that he was a Parselmouth, which meant he could speak to them. "Wait," said Harry. I've seen something about Parselmouths controlling something." He flicked back through Fantastic Beasts. "The Basilisk is a brilliant green serpent that may reach up to fifty feet in length. It has exceptionally venomous fangs but its most dangerous means of attack is the gaze of its large yellow eyes. Anyone looking into these will suffer instant death. Given a suitably large food source, the Basilisk can attain a great age. Herpo the Foul's Basilisk is reported to have lived for nine hundred years." "There's a bit about them being illegal to make, but then it says – "However, since Basilisks are uncontrollable except by Parselmouths, they are as dangerous to most Dark wizards as anybody else.""
Ron's face went pale, and he held up the book he'd been reading from. "It says in here that spiders flee from Basilisks, and that a rooster cry is fatal to them. But if looking it in the eye kills you, how come Mrs Norris didn't die?" "Because it requires direct sight!" Hermione gasped. "There was a puddle on the floor, remember? She saw the reflection of the eyes. And we know how it's getting around, too." "We do?" "A puddle on the floor, Ron. A big puddle. For a puddle that size, inside, the water must have been coming out of the plumbing."
Now all three of them had pale faces. At Hermione's insistence, they put the books back before rushing to find Professor McGonagall. She didn't believe them when they told her theY had worked out what Slytherin's monster was, but she was walking alongside Professor Dumbledore, who did. "I apologise for what you are about to hear," he said, "but I must ensure the school's safety. You may wish to cover your ears." He drew his wand and pointed it at his throat. "Sonorus!" he said. When next Professor Dumbledore spoke, his voice boomed throughout the castle. "ATTENTION. THIS IS PROFESSOR DUMBLEDORE. ALL STUDENTS AND STAFF ARE TO EXIT THE CASTLE IMMEDIATELY AND ASSEMBLE BY THE QUIDDITCH PITCH. PREFECTS AND HEADS OF HOUSE, ORGANISE YOUR HOUSES BY PERFORM A HEAD COUNT. GHOSTS AND PORTRAITS ARE TO ASSEMBLE AT THE BASE OF THE GRAND STAIRCASE UNTIL FURTHER NOTICE."
As they hurried outside, Harry asked "Er, sir? Why are we all going outside?" "It is a space large enough to contain everyone in the school, Harry, and it is not inside. Given what you have just learned about Basilisks, imagine what would happen if it were to emerge, right now, from its hiding place, and proceed to the Great Hall." "They'd – they'd all die, sir." "That would be the case, yes. However, among Hagrid's duties as groundskeeper is dealing with the flock of chickens which provide us with eggs. Since the school has chickens, we have roosters. All that is needed is for us to admit a rooster to the castle with the same spell cast upon it that I just used, and then induce it to crow. The crow will carry throughout the castle, and then the ghosts and portraits shall be requested to search for the Basilisk – including within the plumbing."
A few minutes later, the castle echoed again with the crowing of a rooster. It took all afternoon for the search to be completed, but eventually, Nearly Headless Nick reported that there was a tunnel beneath the sinks in the out-of-order girls' bathroom on the second floor. He had followed it to its end, and had come to a large metal door with snakes on it. Beyond the door was a large chamber with more snake imagery, and a large stone sculpture of Salazar Slytherin's face. Lying in the chamber was a dead Basilisk.