her lifting books as she searched for her rune dictionary.

 "I couldn't do that!" said Hermione, looking scandalized. 

"Arithmancy looks terrible," said Harry, picking up a very complicated-looking number chart.

 "Oh no, it's wonderful!" said Hermione earnestly. "It's my favorite subject! It's --" 

But exactly what was wonderful about Arithmancy, Harry never found out. At that precise moment, a strangled yell echoed down the boys' staircase. The whole common room fell silent, staring, petrified, at the entrance. Then came hurried footsteps, growing louder and louder -- and then Ron came leaping into view, dragging with him a bedsheet. 

"LOOK!" he bellowed, striding over to Hermione's table. 

With a yelp, Amelia fell off her chair. The tall pile of books next to her toppled over onto Amelia. She threw a book off her head. "Ron, what is going on?"

"LOOK!" he yelled, shaking the sheets in her face. 

"Ron, what --?" 

"SCABBERS! LOOK! SCABBERS!" 

Hermione was leaning away from Ron, looking utterly bewildered. Harry looked down at the sheet Ron was holding. There was something red on it. Something that looked horribly like --

 "BLOOD!" Ron yelled into the stunned silence. "HE'S GONE! AND YOU KNOW WHAT WAS ON THE FLOOR?" 

"N -- no," said Hermione in a trembling voice. Amelia rushed over and stood in front of Hermoine, neither of them liked Ron's temper.

 Ron threw something down onto Hermione's rune translation. Hermione and Harry leaned forward. Lying on top of the weird, spiky shapes were several long, ginger cat hairs.