IT'S CHANGED! (SNILY)

The clue

He hid behind the wall, panting. He had run from the dungeons to the upper floors and it was damn tiring. And in the cold, it was even more. He heard someone's faint footsteps and sucked in breath, pressing himself flat on the wall, to escape from the comer's notice.

He frowned when he saw no one coming through the path. He peeked his head out a little to see Filch running in the opposite direction. Another of the students strutting at night. He scoffed. Stupid kids. At least they gave him a way to reach the library.

He was about to keep the next step when his hand brushed through his own cloak and he felt a weight in it. He flipped open his cloak and rolled his eyes on himself. He was almost angry with himself for forgetting to wrap the invisibility cloak around himself. So, that he did, visible nothing more than thin air.

He easily slipped out of the wall and walked through the corridor. He saw Filch again... chasing after someone and shouting something to his cat. Severus didn't pay any heed to it. Must be the stupid kids.

He continued to walk until he reached the library. He approached the book shelves and searched for the ones that said about magical aquatic beings. He searched and searched for that shelf he found one.

Now, through the rows for the correct book on something related to the of lakes in Scotland... better if he found something for winters. He moved his fingers from book titles to next. He sighed and waved his wand for a tempus charm. The time in numbers floated in the air saying, it was half past three. He gasped. He'd been out of the common room for more than an hour. He had to hurry up.

He increased his pace in searching for the right book when he found it. He sighed thankfully and took it out of the shelf.

The Waters of Magical Scotland.

Great. He hurriedly flipped to the part where they were talking about the lakes or such water bodies in winters. Even in such cold weather around him, a droplet of sweat dripped down his forehead. He wiped it away with his sleeve and concentrated again.

He groaned and closed his eyes, taking a deep breath. Panicking is going to take him nowhere. So, he calmed himself and turned the giant tome to the start again to read about the general things that happened in lakes in Scotland.

He was reading when his eyes landed on a chapter denoted to Mer-people.

They lived deep under the lakes... ... ... ... ... ... -Severus' eyes widened- ... ... ... were greatly attracted to music.

Mer-people were attracted to music? That is why he heard that song that seemed to be sung by angels. That meant that the lake wasn't producing any sounds... it was the Mer-person there! They must be singing... but so mesmerizingly?

The Mer-person had shown signs of being fascinated by the screeching noises of the egg. Could they know something? He had to ask them. But for that he had to get into the lake for them to talk about the screeching noise.

He groaned. The other creatures would kill him and eat him as shreds, if he at the very least, placed a foot inside the lake. And then the cold water. That would freeze him to death. Though there must be some spells to protect oneself from that.

He kept the book in its place and began searching for another. In the similar row he found another book.

The Deads in the Waters of Scotland

Severus opened it. Perhaps, it showed about how to survive them with a spell or two. It showed everything about the people who died in the waters without a trace or their being. A shiver ran down Severus' spine. He didn't want to be dead. And not from the deadly creatures that are found there. He read more until he found something.