Malfoy made a grotesque face,

Malfoy made a grotesque face, his mouth sagging open and his eyes rolling. Crabbe and Goyle gave their usual grunts of laughter; Pansy Parkinson shrieked with glee.

Something collided hard with Harry's shoulder, knocking him sideways. A split second later he realised that Neville had just charged past him, heading straight for Malfoy.

‘Neville, no!’

Harry leapt forward and seized the back of Neville's robes; Neville struggled frantically, his fists flailing, trying desperately to get at Malfoy who looked, for a moment, extremely shocked.

‘Help me!’ Harry flung at Ron, managing to get an arm around Neville's neck and dragging him backwards, away from the Slytherins. Crabbe and Goyle were flexing their arms as they stepped in front of Malfoy, ready for the fight. Ron seized Neville's arms, and together he and Harry succeeded in dragging Neville back into the Gryffindor line. Nevilles face was scarlet; the pressure Harry was exerting on his throat rendered him quite incomprehensible, but odd words spluttered from his mouth.

‘Not ... funny ... don't ... Mungo's ... show ... him ...’

The dungeon door opened. Snape appeared there. His black eyes swept up the Gryffindor line to the point where Harry and Ron were wrestling with Neville.

‘Fighting, Potter, Weasley, Longbottom?’ Snape said in his cold, sneering voice. ‘Ten points from Gryffindor. Release Longbottom, Potter, or it will be detention. Inside, all of you.’

Harry let go of Neville, who stood panting and glaring at him.

‘I had to stop you,’ Harry gasped, picking up his bag. ‘Crabbe and Goyle would've torn you apart.’

Neville said nothing; he merely snatched up his own bag and stalked off into the dungeon.

‘What in the name of Merlin,’ said Ron slowly, as they followed Neville, ‘was that about?’

Harry did not answer. He knew exactly why the subject of people who were in St. Mungo's because of magical damage to their brains was highly distressing to Neville, but he had sworn to Dumbledore that he would not tell anyone Neville's secret. Even Neville did not know Harry knew.

Harry, Ron and Hermione took their usual seats at the back of the class, pulled out parchment, quills and their copies of One Thousand Magical Herbs and Fungi.The class around them was whispering about what Neville had just done, but when Snape closed the dungeon door with an echoing bang, everybody immediately fell silent.

‘You will notice,’ said Snape, in his low, sneering voice, ‘that we have a guest with us today.’

He gestured towards the dim corner of the dungeon and Harry saw Professor Umbridge sitting there, clipboard on her knee. He glanced sideways at Ron and Hermione, his eyebrows raised. Snape and Umbridge, the two teachers he hated most. It was hard to decide which one he wanted to triumph over the other.

‘We are continuing with our Strengthening Solution today. You will find your mixtures as you left them last lesson; it correctly made they should have matured well over the weekend—instructions—’ he waved his wand again ‘—on the board. Carry on.’

Professor Umbridge spent the first half hour of the lesson making notes in her corner. Harry was very interested in hearing her question Snape; so interested, that he was becoming careless with his potion again.

‘Salamander blood, Harry!’ Hermione moaned, grabbing his wrist to prevent him adding the wrong ingredient for the third time, ‘not pomegranate juice!’

‘Right,’ said Harry vaguely, putting down the bottle and continuing to watch the corner. Umbridge had just got to her feet. ‘Ha,’ he said softly, as she strode between two lines of desks towards Snape, who was bending over Dean Thomas's cauldron.

‘Well, the class seem fairly advanced for their level,’ she said briskly to Snape's back. ‘Though I would question whether it is advisable to teach them a potion like the Strengthening Solution. I think the Ministry would prefer it if that was removed from the syllabus.’

Snape straightened up slowly and turned to look at her.

‘Now ... how long have you been teaching at Hogwarts?’ she asked, her quill poised over her clipboard.

‘Fourteen years,’ Snape replied. His expression was unfathomable. Harry, watching him closely, added a few drops to his potion; it hissed menacingly and turned from turquoise to orange.

‘You applied first for the Defence Against the Dark Arts post, I believe?’ Professor Umbridge asked Snape.

‘Yes,’ said Snape quietly.

‘But you were unsuccessful?’

Snape's lip curled.

‘Obviously.’

Professor Umbridge scribbled on her clipboard.

‘And you have applied regularly for the Defence Against the Dark Arts post since you first joined the school, I believe?’

‘Yes,’ said Snape quietly, barely moving his lips. He looked very angry.

‘Do you have any idea why Dumbledore has consistently refused to appoint you?’ asked Umbridge.

‘I suggest you ask him,’ said Snape jerkily.

‘Oh, I shall,’ said Professor Umbridge, with a sweet smile.

‘I suppose this is relevant?’ Snape asked, his black eyes narrowed.

‘Oh yes,’ said Professor Umbridge, ‘yes, the Ministry wants a thorough understanding of teachers'—er—backgrounds.’

She turned away, walked over to Pansy Parkinson and began questioning her about the lessons. Snape looked round at Harry and their eyes met for a second. Harry hastily dropped his gaze to his potion, which was now congealing foully and giving off a. strong smell of burned rubber.

‘No marks again, then, Potter,’ said Snape maliciously, emptying Harry's cauldron with a wave of his wand. ‘You will write me an essay on the correct composition of this potion, indicating how and why you went wrong, to be handed in next lesson, do you understand?’

‘Yes,’ said Harry furiously. Snape had already given them homework and he had Quidditch practice this evening; this would mean another couple of sleepless nights. It did not seem possible that he had awoken that morning feeling very happy. All he felt now was a fervent desire for this day to end.

‘Maybe I'll skive off Divination,’ he said glumly, as they stood in the courtyard after lunch, the wind whipping at the hems of robes and brims of hats. ‘I'll pretend to be ill and do Snape's essay instead, then I won't have to stay up half the night.’

‘You can't skive off Divination,’ said Hermione severely.