"Yes!" hissed Potter. "I think this is it!"
Leo dashed over to find that they'd managed to pull a page from Granger's grip. It was quite clearly page seven hundred and twenty-four of Most Macabre Monstrosities. He began to read:
Of the many fearsome beasts and monsters that roam our land, there is none more curious or more deadly than the Basilisk, known also as the King of Serpents. This snake, which may reach gigantic size and live many hundreds of years, is born from a chicken's egg, hatched beneath atoad. 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 crowing of therooster, which is fatal to it.
"But then," asked Potter, "how are those people all still alive?"
Leo's mind was racing ten steps ahead. "Did any of them actually see it directly? If they saw a reflection or something – "
"Yes!" said Potter. "Colin Creevey had a camera – he must have seen the Basilisk through it – the camera was destroyed, but he was only Petrified!"
"The mirror!" said Weasley. "Hermione and Marisa and that Ravenclaw prefect – if she'd found out, she'd tell the first people she met to look around a corner with a mirror, and then – "
Leo really didn't want to hear about that, but he had already worked out the next one: "Finch-Fletchley must have seen the Basilisk through the Gryffindor ghost – what's his name – Nearly-Headless Nick."
"Nick got the full blast of it, but he's already dead, he couldn't die again!"
"And Mrs. Norris…" began Weasley.
"The bathroom was flooded that night," said Potter. "She could have seen it through the reflection."
"Yes! And Hagrid's roosters were killed, and he said something about the spiders…"
"But how's it been getting around with no-one noticing it?" asked Leo.
Potter pointed to a word he hadn't noticed before, in Granger's handwriting: pipes.
"Oh! It all fits, this has to be it! It's a basilisk!"
"What do we do now?" asked Potter.
"Tell a teacher," said Weasley immediately.
"Not yet," said Leo. "First, we need to see if we have any other clues to tell us about the Heir. What can you tell me about the diary?"
"Oh, that," said Potter.
"Are you sure we can trust you?" asked Weasley.
"Look," said Leo, exasperated, "if I was the Heir, I wouldn't have given you the information about the missing page, would I?"
"The diary," said Potter, "belongs to a student called Tom Riddle…"
And he explained how it had shown him the memory of Riddle's capture of Hagrid, and how they'd later discovered that Hagrid hadn't done it (he was slightly cagey about how that had happened; Leo had the feeling it involved more rule-breaking).
"Have you worked out who stole it?" asked Leo. He still wasn't sure whether there was a definite connection between the diary and the attacks, but it was certainly worth investigating.
"It has to be a Gryffindor – only they know our password."
"That's… not very helpful. There's about a hundred Gryffindors in the school, and that's not even counting the teachers. Who knew you had it?"
"The only time anyone else saw it… I suppose it could have been someone from our dorm… but Valentine's Day."
"There were just a few first-years…" said Leo. "That prefect, is he your brother, Weasley?"
Weasley nodded.
"Wait… don't you have a sister who's first-year Gryffindor?" asked Leo.
"Yeah – Ginny – blimey, you're not suggesting – "
"No," said Leo hastily, "but I thought she might have noticed something if one of her classmates was acting oddly or something. Ask her about it. Subtly."
"And shall we tell a teacher about the basilisk?"
Leo shook his head. "Not yet," he said. "We need to keep everything a secret. There's a chance the Heir could figure out we're onto him. We work in complete secrecy, and only when we have a specific name do we go to any teachers."
They might have argued, but Leo's tone and the look on his face were enough to convince them.
"We'd better get to class, then," said Potter, and he and Weasley left for Defence.
Leo lingered a little longer. He moved from Granger's bed over to Marisa's and placed his hand on hers for a brief second, and then he left.