A mysterious treasure hunt / Part.1 PV Fin.

After a nap in the common room, Lilas had a sudden urge to explore the castle. She was new to the school and trying to understand better what was surrouding her. After a quick walk in the corridors and a turbulent passage by the stairs, she entered the second floor. It was silent as the pupils were on free time. She only met a group of fifth year getting out of the study room. Strange statues and a dusty smell led her through the dark hall to a room she had never heard about before.
It looked like a lavatory, but it was really dirty. There was no one, and she could only hear the sound of water dripping down a sink. By coincidence, she hadn't gone to the bathroom in the whole day so she tried to find a decent cabin. After a litte inspection, she finally found a cabin clean enough and locked the door.
She dropped a small bag she had been carrying (containing a snack, a Muggle camera offered by her father and a notebook), but when she looked down at it, she noticed something hidden behind the pipings of the toilet. It was a humid parchment, rolled up and slipped between two pipes. She unrolled it and tried to read the notes despite the numerous water drops that had made some of the lines compltely unreadable.
The parchment was in a poor condition. Though, Lilas managed to decrypt some words :

"…… Amber…my third year……………last………hidden in the castle…never………papers……find and see………owlery……………second note……game rules…"

In the end, there was a date scribbled with a pencil, that didn't seem to have been damaged by water or time :
"January 23rd"
Lilas frowned. What was that ? Who was the autor ? Who on Earth could Amber be ? She knew some students named Amber, but none of them were in third yeard. Strange… She decided to go to the owlery in order to look for the second paper.