He took several paces back from the dais and wrenched his eyes from the veil.

He took several paces back from the dais and wrenched his eyes from the veil.

‘Let's go,’ he said.

‘That's what I've been trying to—well, come on, then!’ said Hermione, and she led the way back around the dais. On the other side, Ginny and Neville were staring, apparently entranced, at the veil too. Without speaking, Hermione took hold of Ginny's arm,

Ron grabbed Neville's, and they marched them firmly back to the lowest stone bench and clambered all the way back up to the door.

‘What d'you reckon that arch was?’ Harry asked Hermione as they regained the dark circular room.

‘I don't know, but whatever it was, it was dangerous,’ she said firmly, again inscribing a fiery cross on the door.

Once more, the wall span and became still again. Harry approached another door at random and pushed. It did not move.

‘What's wrong?’ said Hermione.

‘It's ... locked ...’ said Harry, throwing his weight at the door, but it didn't budge.

‘This is it, then, isn't it?’ said Ron excitedly, joining Harry in the attempt to force the door open. ‘Bound to be!’

‘Get out of the way!’ said Hermione sharply. She pointed her wand at the place where a lock would have been on an ordinary door and said, ‘Alohomora!’

Nothing happened.

‘Sirius's knife!’ said Harry. He pulled it out from inside his robes and slid it into the crack between the door and the wall. The others all watched eagerly as he ran it from top to bottom, withdrew it and then flung his shoulder again at the door. It remained as firmly shut as ever. What was more, when Harry looked down at the knife, he saw the blade had melted.

‘Right, we're leaving that room,’ said Hermione decisively.

‘But what if that's the one?’ said Ron, staring at it with a mixture of apprehension and longing.

‘It can't be, Harry could get through all the doors in his dream,’ said Hermione, marking the door with another fiery cross as Harry replaced the now-useless handle of Sirius's knife in his pocket.

‘You know what could be in there?’ said Luna eagerly, as the wall started to spin yet again.

‘Something blibbering, no doubt,’ said Hermione under her breath and Neville gave a nervous little laugh.

The wall slid to a halt and Harry, with a feeling of increasing desperation, pushed the next door open.

‘This is it!’

He knew it at once by the beautiful, dancing, diamond-sparkling light. As Harry's eyes became accustomed to the brilliant glare, he saw clocks gleaming from every surface, large and small, grandfather and carriage, hanging in spaces between the bookcases or standing on desks ranging the length of the room, so that a busy, relentless ticking filled the place like thousands of minuscule, marching footsteps. The source of the dancing, diamond-bright light was a towering crystal bell jar that stood at the far end of the room.

‘This way!’

Harry's heart was pumping frantically now that he knew they were on the right track; he led the way down the narrow space between the lines of desks, heading, as he had done in his dream, for the source of the light, the crystal bell jar quite as tall as he was that stood on a desk and appeared to be full of a billowing, glittering wind.

‘Oh, took!’ said Ginny, as they drew nearer, pointing at the very heart of the bell jar.

Drifting along in the sparkling current inside was a tiny, jewel-bright egg. As it rose in the jar, it cracked open and a hummingbird emerged, which was carried to the very top of the jar, but as it fell on the draught its feathers became bedraggled and damp again, and by the time it had been borne back to the bottom of the jar it had been enclosed once more in its egg.

‘Keep going!’ said Harry sharply, because Ginny showed signs of wanting to stop and watch the egg's progress back into a bird.

‘You dawdled enough by that old arch!’ she said crossly, but followed him past the bell jar to the only door behind it.

‘This is it,’ Harry said again, and his heart was now pumping so hard and fast he felt it must interfere with his speech, ‘it's through here—’

He glanced around at them all; they had their wands out and looked suddenly serious and anxious. He looked back at the door and pushed. It swung open.