Harry was so relieved she was taking him seriously that he did not hesitate, but jumped out of bed at once, pulled on his dressing gown and pushed his glasses back on to his nose.

'Weasley, you ought to come too,' said Professor McGonagall.

They followed Professor McGonagall past the silent figures of Neville, Dean and Seamus, out of the dormitory down the spiral stairs into the common room, through the portrait hole and off along the Fat Lady's moonlit corridor. Harry felt as though the panic inside him might spill over at any moment; he wanted to run, to yell for Dumbledore; Mr Weasley was bleeding as they walked along so sedately and what if those fangs (Harry tried hard not to think 'my fangs') had been poisonous? They passed Mrs Norris, who turned her lamplike eyes upon them and hissed faintly but Professor McGonagall said, 'Shoo!' Mrs Norris slunk away into the shadows, and in a few minutes they had reached the stone gargoyle guarding the entrance to Dumbledore s office.

'Fizzing Whizzbee,' said Professor McGonagall.

The gargoyle sprang to life and leapt aside; the wall behind it split in two to reveal a stone staircase that was moving continually upwards like a spiral escalator. The three of them stepped on to the moving stairs; the wall closed behind them with a thud and they were moving upwards in tight circles until they reached the highly polished oak door with the brass knocker shaped like a griffin.

Though it was now well past midnight there were voices coming from inside the room, a positive babble of them. It sounded as though Dumbledore was entertaining at least a dozen people.

Professor McGonagall rapped three times with the griffin knocker and the voices ceased abruptly as though someone had switched them all off. The door opened of its own accord and Professor McGonagall led Harry and Ron inside.

The room was in half-darkness; the strange silver instruments standing on tables were silent and still rather than whirring and emitting puffs of smoke as they usually did; the portraits of old headmasters and headmistresses covering the walls were all snoozing in their frames. Behind the door, a magnificent red and gold bird the size of a swan dozed on its perch with its head under its wing.

'Oh, it's you, Professor McGonagall . . . and . . . ah. '

Dumbledore was sitting in a high-backed chair behind his desk; he leaned forward into the pool of candlelight illuminating the papers laid out before him. He was wearing a magnificently embroidered purple and gold dressing gown over a snowy white nightshirt, but seemed wide-awake, his penetrating light blue eyes fixed intently upon Professor McGonagall.

'Professor Dumbledore, Potter has had a . . . well, a nightmare,' said Professor McGonagall. 'He says . . .'

'It wasn't a nightmare,' said Harry quickly.

Professor McGonagall looked round at Harry, frowning slightly.

'Very well, then, Potter, you tell the Headmaster about it.'

'I . . . well, I was asleep . . .' said Harry and, even in his terror and his desperation to make Dumbledore understand, he felt slightly irritated that the Headmaster was not looking at him, but examining his own interlocked fingers. 'But it wasn't an ordinary dream . . . it was real . . . I saw it happen . . .' He took a deep breath, 'Ron's dad — Mr Weasley — has been attacked by a giant snake.'

The words seemed to reverberate in the air after he had said them, sounding slightly ridiculous, even comic. There was a pause in which Dumbledore leaned back and stared meditatively at the ceiling. Ron looked from Harry to Dumbledore, white-faced and shocked.

'How did you see this?' Dumbledore asked quietly, still not looking at Harry.

'Well . . . I don't know,' said Harry, rather angrily — what did it matter? 'Inside my head, I suppose — '

'You misunderstand me,' said Dumbledore, still in the same calm tone. 'I mean . . . can you remember — er — where you were positioned as you watched this attack happen? Were you perhaps standing beside the victim, or else looking down on the scene from above?'

This was such a curious question that Harry gaped at Dumbledore; it was almost as though he knew . . .

'I was the snake,' he said. 'I saw it all from the snake's point of view.'

Nobody else spoke for a moment, then Dumbledore, now looking at Ron who was still whey-faced, asked in a new and sharper voice, 'Is Arthur seriously injured?'

'Yes,' said Harry emphatically — why were they all so slow on the uptake, did they not realise how much a person bled when fangs that long pierced their side? And why could Dumbledore not do him the courtesy of looking at him?

But Dumbledore stood up, so quickly it made Harry jump, and addressed one of the old portraits hanging very near the ceiling. 'Everard?' he said sharply. 'And you too, Dilys!'

A sallow-faced wizard with a short black fringe and an elderly witch with long silver ringlets in the frame beside him, both of whom seemed to have been in the deepest of sleeps, opened their eyes immediately.

'You were listening?' said Dumbledore.

The wizard nodded; the witch said, 'Naturally.'

'The man has red hair and glasses,' said Dumbledore. 'Everard, you will need to raise the alarm, make sure he is found by the right people — '

Both nodded and moved sideways out of their frames, but instead of emerging in neighbouring pictures (as usually happened at Hogwarts) neither reappeared. One frames now contained nothing but a backdrop of dark curtain, the other a handsome leather armchair. Harry noticed that many of the other headmasters and mistresses on the walls, though snoring and drooling most convincingly, kept sneaking peeks at him from under their eyelids, and he suddenly understood who had been talking when they had knocked.

'Everard and Dilys were two of Hogwartss most celebrated Heads,' Dumbledore said, now sweeping around Harry, Ron and Professor McGonagall to approach the magnificent sleeping bird on his perch beside the door. 'Their renown is such that both have portraits hanging in other important wizarding institutions. As they are free to move between their own portraits, they can tell us what may be happening elsewhere . . .'

'But Mr Weasley could be anywhere!' said Harry.

'Please sit down, all three of you,' said Dumbledore, as though Harry had not spoken, 'Everard and Dilys may not be back for several minutes. Professor McGonagall, if you could draw up extra chairs.'

Professor McGonagall pulled her wand from the pocket of her dressing gown and waved it; three chairs appeared out of thin air, straight-backed and wooden, quite unlike the comfortable chintz armchairs that Dumbledore had conjured up at Harry's hearing. Harry sat down, watching Dumbledore over his shoulder. Dumbledore was now stroking Fawkes's plumed golden head with one finger. The phoenix awoke immediately. He stretched his beautiful head high and observed Dumbledore through bright, dark eyes.

'We will need,' Dumbledore said very quietly to the bird, 'a warning.'

There was a flash of fire and the phoenix had gone.

Dumbledore now swooped down upon one of the fragile silver instruments whose function Harry had never known, carried it over to his desk, sat down facing them again and tapped it gently with the tip of his wand.

The instrument tinkled into life at once with rhythmic clinking noises. Tiny puffs of pale green smoke issued from the minuscule silver tube at the top. Dumbledore watched the smoke closely, his brow furrowed. After a few seconds, the tiny puffs became a steady stream of smoke that thickened and coiled in the air . . . a serpent's head grew out of the end of it, opening its mouth wide. Harry wondered whether the instrument was confirming his story: he looked eagerly at Dumbledore for a sign that he was right, but Dumbledore did not look up.

'Naturally, naturally,' murmured Dumbledore apparently to himself, still observing the stream of smoke without the slightest sign of surprise. 'But in essence divided?'

Harry could make neither head nor tail of this question. The smoke serpent, however, split itself instantly into two snakes, both coiling and undulating in the dark air. With a look of grim satisfaction, Dumbledore gave the instrument another gentle tap with his wand: the clinking noise slowed and died and the smoke serpents grew faint, became a formless haze and vanished.

Dumbledore replaced the instrument on its spindly little table. Harry saw many of the old headmasters in the portraits follow him with their eyes, then, realising that Harry was watching them, hastily pretend to be sleeping again. Harry wanted to ask what the strange silver instrument was for, but before he could do so, there was a shout from the top of the wall to their right; the wizard called Everard had reappeared in his portrait., panting slightly.

'Dumbledore!'

'What news?' said Dumbledore at once.

'I yelled until someone came running,' said the wizard, who was mopping his brow on the curtain behind him, 'said I'd heard something moving downstairs — they weren't sure whether to believe me but went down to check — you know there are no portraits down there to watch from. Anyway, they carried him up a few minutes later. He doesn't look good, he's covered in blood, I ran along to Elfrida Cragg's portrait to get a good view as they left — '

'Good,' said Dumbledore as Ron made a convulsive movement. 'I take it Dilys will have seen him arrive, then — '

And moments later, the silver-ringleted witch had reappeared in her picture, too; she sank, coughing, into her armchair and said, 'Yes, they've taken him to St Mungo's, Dumbledore . . . they carried him past my portrait . . . he looks bad . . .'

'Thank you,' said Dumbledore. He looked round at Professor McGonagall.

'Minerva, I need you to go and wake the other Weasley children.'

'Of course . . .'

Professor McGonagall got up and moved swiftly to the door. Harry cast a sideways glance at Ron, who was looking terrified.

'And Dumbledore — what about Molly?' said Professor McGonagall, pausing at the door.

'That will be a job for Fawkes when he has finished keeping a lookout for anybody approaching,' said Dumbledore. 'But she may already know . . . that excellent clock of hers . . .'

Harry knew Dumbledore was referring to the clock that told, not the time, but the whereabouts and conditions of the various Weasley family members, and with a pang he thought that Mr Weasley's hand must, even now, be pointing at mortal peril. But it was very late. Mrs Weasley was probably asleep, not watching the clock. Harry felt cold as he remembered Mrs Weasley's Boggart turning into Mr Weasley's lifeless body, his glasses askew, blood running down his face . . . but Mr Weasley wasn't going to die . . . he couldn't . . .