Harry Potter 05 - Harry Potter and the Order of the Phoenix

there was a great rumbling noise and the candles began to move sideways. The circular wall was rotating.
    Hermione grabbed Harry’s arm as though frightened the floor might move, too, but it did not. For a few seconds, the blue flames around them were blurred to resemble neon lines as the wall sped around; then, quite as suddenly as it had started, the rumbling stopped and everything became stationary once again.
    Harry’s eyes had blue streaks burned into them; it was all he could see.
    ‘What was that about?’ whispered Ron fearfully.
    ‘I think it was to stop us knowing which door we came in through,’ said Ginny in a hushed voice.
    Harry realised at once she was right: he could no sooner identify the exit door than locate an ant on the jet-black floor; and the door through which they needed to proceed could be any one of the dozen surrounding them.
    ‘How’re we going to get back out?’ said Neville uncomfortably.
    ‘Well, that doesn’t matter now,’ said Harry forcefully, blinking to try to erase the blue lines from his vision, and clutching his wand tighter than ever, ‘we won’t need to get out till we’ve found Sirius –’
    ‘Don’t go calling for him, though!’ Hermione said urgently; but Harry had never needed her advice less, his instinct was to keep as quiet as possible.
    ‘Where do we go, then, Harry?’ Ron asked.
    ‘I don’t –’ Harry began. He swallowed. ‘In the dreams I went through the door at the end of the corridor from the lifts into a dark room – that’s this one – and then I went through another door into a room that kind of … glitters. We should try a few doors,’ he said hastily, ‘I’ll know the right way when I see it. C’mon.’
    He marched straight at the door now facing him, the others following close behind him, set his left hand against its cool, shining surface, raised his wand ready to strike the moment it opened, and pushed.
    It swung open easily.
    After the darkness of the first room, the lamps hanging low on golden chains from this ceiling gave the impression that this long rectangular room was much brighter, though there were no glittering, shimmering lights as Harry had seen in his dreams. The place was quite empty except for a few desks and, in the very middle of the room, an enormous glass tank of deep green liquid, big enough for all of them to swim in; a number of pearly-white objects were drifting around lazily in it.
    ‘What’re those things?’ whispered Ron.
    ‘Dunno,’ said Harry.
    ‘Are they fish?’ breathed Ginny.
    ‘Aquavirius Maggots!’ said Luna excitedly. ‘Dad said the Ministry were breeding –’
    ‘No,’ said Hermione. She sounded odd. She moved forward to look through the side of the tank. ‘They’re brains.’
    ‘Brains?’
    ‘Yes … I wonder what they’re doing with them?’
    Harry joined her at the tank. Sure enough, there could be no mistake now he saw them at close quarters. Glimmering eerily, they drifted in and out of sight in the depths of the green liquid, looking something like slimy cauliflowers.
    ‘Let’s get out of here,’ said Harry. ‘This isn’t right, we need to try another door.’
    ‘There are doors here, too,’ said Ron, pointing around the walls. Harry’s heart sank; how big was this place?
    ‘In my dream I went through that dark room into the second one,’ he said. ‘I think we should go back and try from there.’
    So they hurried back into the dark, circular room; the ghostly shapes of the brains were now swimming before Harry’s eyes instead of the blue candle flames.
    ‘Wait!’ said Hermione sharply, as Luna made to close the door of the brain room behind them. ‘Flagrate!’
    She drew with her wand in midair and a fiery ‘X’ appeared on the door. No sooner had the door clicked shut behind them than there was a great rumbling, and once again the wall began to revolve very fast, but now there was a great red-gold blur in amongst the faint blue and, when all became still again, the fiery cross still burned, showing the door they had already tried.
    ‘Good thinking,’ said Harry. ‘OK, let’s try this one –’
    Again, he strode directly at the door facing him and pushed it open, his wand still raised, the others at his heels.
    This room was larger than the last, dimly lit and rectangular, and the centre of it was sunken, forming a great stone pit some twenty feet deep. They were standing on the topmost tier of what seemed to be stone benches running all