The rain had started just after dinner. Not the usual Scottish drizzle that clung to the castle stones like mist, but heavy rain — thick silver sheets crashing against the windows hard enough to rattle them in their frames. Thunder rolled somewhere over the mountains, deep and slow.

Which was exactly why this was a terrible idea.

“You do realize,” Remus said for what had to be the fifth time, “that every version of this story ends with someone dying.”

James grinned, shoving his hands into his coat pockets as they hurried through the corridor. “That’s what makes it interesting.”

“Says the person least likely to die,” Sirius Black muttered.

“You’re both encouraging this,” Remus accused.

“I’m absolutely not,” Sirius replied instantly. “I’m just attending to witness the stupidity firsthand.”

Ahead of them, our character walked faster, excitement bright in their face despite the storm shaking the castle around them. “Come on, Moony. You’ve heard the story too.”

“Everyone’s heard the story.”

And everyone at Hogwarts knew not to go near the Black Lake during storms.

Especially storms like this.

The myth was old — older than most of the ghosts in the castle. Centuries ago, a Hogwarts student vanished beneath the lake during a thunderstorm. Some said he drowned. Others claimed the merpeople dragged him under after he tried to prove he could survive in the depths.

But the creepiest version

The version whispered by first-years late at night—

said the boy never died at all.

When rain fell hard enough, when the lake turned black and violent, he rose from the water as something enormous.

A siren.

Not beautiful like the paintings in old wizard books.

Huge.

Wrong.

A creature with too many teeth, glowing eyes, and a voice that sounded like someone you loved calling your name from underwater.

Remus hated the story.