‘No, you can’t,’ said Malfoy, his wand hand shaking very badly indeed. ‘Nobody can. He told me to do it or he’ll kill me. I’ve got no choice.’

‘Come over to the right side, Draco, and we can hide you more completely than you can possibly imagine. What is more, I can send members of the Order to your mother tonight to hide her likewise. Your father is safe at the moment in Azkaban… when the time comes we can protect him too… come over to the right side, Draco… you are not a killer…’

Malfoy stared at Dumbledore.

‘But I got this far, didn’t I?’ he said slowly. They thought I’d die in the attempt, but I’m here… and you’re in my power… I’m the one with the wand… you’re at my mercy…‘

‘No, Draco,’ said Dumbledore quietly. ‘It is my mercy, and not yours, that matters now.’

Malfoy did not speak. His mouth was open, his wand hand still trembling. Harry thought he saw it drop by a fraction But suddenly footsteps were thundering up the stairs and a second later Malfoy was buffeted out of the way as four people in black robes burst through the door on to the ramparts. Still paralysed, his eyes staring unblinkingly, Harry gazed in terror upon four strangers: it seemed the Death Eaters had won the fight below.

A lumpy-looking man with an odd lopsided leer gave a wheezy giggle.

‘Dumbledore cornered!’ he said, and he turned to a stocky little woman who looked as though she could be his sister and who was grinning eagerly. ‘Dumbledore wandless, Dumbledore alone! Well done, Draco, well done!’

‘Good evening, Amycus,’ said Dumbledore calmly, as though welcoming the man to a tea party. ‘And you’ve brought Alecto too… charming…’

The woman gave an angry little titter.

Think your little jokes’ll help you on your death bed, then?‘ she jeered.

‘Jokes? No, no, these are manners,’ replied Dumbledore.

‘Do it,’ said the stranger standing nearest to Harry, a big, rangy man with matted grey hair and whiskers, whose black Death Eater’s robes looked uncomfortably tight. He had a voice like none that Harry had ever heard: a rasping bark of a voice. Harry could smell a powerful mixture of dirt, sweat and, unmistakeably, of blood coming from him. His filthy hands had long yellowish nails.

‘Is that you, Fenrir?’ asked Dumbledore.

That’s right,‘ rasped the other. ’Pleased to see me, Dumbledore?‘

‘No, I cannot say that I am…’

Fenrir Greyback grinned, showing pointed teeth. Blood trickled down his chin and he licked his lips slowly, obscenely.

‘But you know how much I like kids, Dumbledore.’

‘Am I to take it that you are attacking even without the full moon now? This is most unusual… you have developed a taste for human flesh that cannot be satisfied once a month?’

That’s right,‘ said Greyback. ’Shocks you, that, does it, Dumbledore? Frightens you?‘

‘Well, I cannot pretend it does not disgust me a little,’ said Dumbledore. ‘And, yes, I am a little shocked that Draco here invited you, of all people, into the school where his friends live…’

‘I didn’t,’ breathed Malfoy. He was not looking at Greyback; he did not seem to want to even glance at him. ‘I didn’t know he was going to come -’

‘I wouldn’t want to miss a trip to Hogwarts, Dumbledore,’ rasped Greyback. ‘Not when there are throats to be ripped out… delicious, delicious…’

And he raised a yellow fingernail and picked at his front teeth, leering at Dumbledore.

‘I could do you for afters, Dumbledore…’

‘No,’ said the fourth Death Eater sharply. He had a heavy, brutal-looking face. ‘We’ve got orders. Draco’s got to do it. Now, Draco, and quickly.’

Malfoy was showing less resolution than ever. He looked terrified as he stared into Dumbledore’s face, which was even paler, and rather lower than usual, as he had slid so far down the rampart wall.

‘He’s not long for this world anyway, if you ask me!’ said the lopsided man, to the accompaniment of his sister’s wheezing giggles. ‘Look at him — what’s happened to you, then, Dumby?’

‘Oh, weaker resistance, slower reflexes, Amycus,’ said Dumbledore. ‘Old age, in short… one day, perhaps, it will happen to you… if you are lucky…’

‘What’s that mean, then, what’s that mean?’ yelled the Death Eater, suddenly violent. ‘Always the same, weren’t yeh, Dumby, talking and doing nothing, nothing, I don’t even know why the Dark Lord’s bothering to kill yeh! Come on, Draco, do it!’

But at that moment, there were renewed sounds of scuffling from below and a voice shouted, ‘They’ve blocked the stairs — Reducto! REDUCTO!’

Harry’s heart leapt: so these four had not eliminated all opposition, but merely broken through the fight to the top of the Tower, and, by the sound of it, created a barrier behind them ‘Now, Draco, quickly!’ said the brutal-faced man angrily.

But Malfoy’s hand was shaking so badly that he could barely aim.

Til do it,‘ snarled Greyback, moving towards Dumbledore with his hands outstretched, his teeth bared.

‘I said no!’ shouted the brutal-faced man; there was a flash of light and the werewolf was blasted out of the way; he hit the ramparts and staggered, looking furious. Harry’s heart was hammering so hard it seemed impossible that nobody could hear him standing there, imprisoned by Dumbledore’s spell -if he could only move, he could aim a curse from under the Cloak ‘Draco, do it, or stand aside so one of us -’ screeched the woman, but at that precise moment the door to the ramparts burst open once more and there stood Snape, his wand clutched in his hand as his black eyes swept the scene, from Dumbledore slumped against the wall, to the four Death Eaters, including the enraged werewolf, and Malfoy.

‘We’ve got a problem, Snape,’ said the lumpy Amycus, whose eyes and wand were fixed alike upon Dumbledore, ‘the boy doesn’t seem able -’

But somebody else had spoken Snape’s name, quite softly.

‘Severus…’

The sound frightened Harry beyond anything he had experienced all evening. For the first time, Dumbledore was pleading.

Snape said nothing, but walked forwards and pushed Malfoy roughly out of the way. The three Death Eaters fell back without a word. Even the werewolf seemed cowed.

Snape gazed for a moment at Dumbledore, and there was revulsion and hatred etched in the harsh lines of his face.

‘Severus… please…“

Snape raised his wand and pointed it directly at Dumbledore.

‘Avada Kedavra!’

A jet of green light shot from the end of Snape’s wand and hit Dumbledore squarely in the chest. Harry’s scream of horror never left him; silent and unmoving, he was forced to watch as Dumbledore was blasted into the air: for a split second he seemed to hang suspended beneath the shining skull, and then he fell slowly backwards, like a great rag doll, over the battlements and out of sight.