but Squibs are quite unusual. If Filch's trying to learn magic from a Kwikspell course, I reckon he must be a Squib. It would explain a lot. Like why he hates students so much.' Ron gave a satisfied smile. 'He's bitter.'

A clock chimed somewhere.

'Midnight,' said Harry. 'We'd better get to bed before Snape comes along and tries to frame us for something else.'

*
For a few days, the school could talk of little but the attack on

Mrs Norris. Filch kept it fresh in everyone's minds by pacing the spot where she had been attacked, as though he thought the attacker might come back. Harry had seen him scrubbing the message on the wall with 'Mrs Skower's All-Purpose Magical Mess Remover', but to no effect; the words still gleamed as brightly as ever on the stone. When Filch wasn't guarding the scene of the crime, he was skulking red-eyed through the corridors, lunging out at unsuspecting students and trying to put them in detention for things like 'breathing loudly' and 'looking happy'.

Ginny Weasley seemed very disturbed by Mrs Norris's fate. According to Ron, she was a great cat-lover.

'But you hadn't really got to know Mrs Norris,' Ron told her bracingly. 'Honestly, we're much better off without her.' Ginny's lip trembled. 'Stuff like this doesn't often happen at Hogwarts,' Ron assured her. 'They'll catch the nutter who did it and have him out of here in no time. I just hope he's got time to Petrify Filch before he's expelled. I'm only joking –' Ron added hastily, as Ginny blanched. Amelia smacked Ron upside the head.

The attack had also had an effect on Hermione. It was quite usual for Hermione to spend a lot of time reading, but she was now doing almost nothing else. Nor could Harry and Ron get much response from her when they asked what she was up to, and not until the following Wednesday did they find out. Amelia seemed to have her nose in books more often as well.

Harry had been held back in Potions, where Snape had made him stay behind to scrape tubeworms off the desks. After a huried lunch, he went upstairs to meet Ron in the library, and saw Justin Finch-Fletchley, the Hufflepuff boy from Herbology, coming towards him. Harry had just opened his mouth to say hello when Justin caught sight of him, turned abruptly and sped off in the opposite direction.

Harry found Ron at the back of the library, measuring his