'Now, don't forget that nice wrist movement we've been practising!' squeaked Professor Flitwick, perched on top of his pile of books as usual. 'Swish and flick, remember, swish and flick. And saying the magic words properly is very important, too never forget Wizard Baruffio, who said 's' instead of 'f' and found himself on the floor with a buffalo on his chest.'

It was very difficult. Harry and Seamus swished and flicked, but the feather they were supposed to be sending skywards just lay on the desktop. Seamus got so impatient that he prodded it with his wand and set fire to it Harry had to put it out with his hat.

Ron, at the next table, wasn't having much more luck.

'Wingardium Leviosa!' he shouted, waving his long arms like a windmill.

'You're saying it wrong,' Harry heard Hermione snap. 'It's Wing-gar-dium Levi-o-sa, make the "gar" nice and long.'

'You do it, then, if you're so clever,' Ron snarled.

Hermione rolled up the sleeves of her gown, flicked her wand and said, 'Wingardium Leviosa!'

Their feather rose off the desk and hovered about four feet above their heads.

'Oh, well done!' cried Professor Flitwick, clapping. 'Everyone see here, Miss Granger's done it!'

Ron was in a very bad temper by the end of the class.

'It's no wonder no one can stand her,' he said to Harry as they pushed their way into the crowded corridor. 'She's a nightmare, honestly.'

Someone knocked into Harry as they hurried past him. It was Hermione. Harry caught a glimpse of her face and was startled to see that she was in tears.

'I think she heard you.'

'So?' said Ron, but he looked a bit uncomfortable. 'She must've noticed she's got no friends.'

Hermione didn't turn up for the next class and wasn't seen all afternoon. On their way down to the Great Hall for the Hallowe'en feast, Harry and Ron overheard Parvati Patil telling her friend Lavender that Hermione was crying in the girls' toilets and wanted to be left alone. Ron looked still more awkward at this, but a moment later they had entered the Great Hall, where the Hallowe'en decorations put Hermione out of their minds.

A thousand live bats fluttered from the walls and ceiling while a thousand more swooped over the tables in low black clouds, making the candles in the pumpkins stutter. The feast appeared suddenly on the golden plates, as it had at the start-of-term banquet.

Harry was just helping himself to a jacket potato when Professor Quirrell came sprinting into the Hall, his turban askew and terror on his face. Everyone stared as he reached Professor Dumbledore's chair, slumped against the table and gasped, 'Troll in the dungeons thought you ought to know.'

He then sank to the floor in a dead faint.

There was uproar. It took several purple firecrackers exploding from the end of Professor Dumbledore's wand to bring silence.

'Prefects,' he rumbled, 'lead your houses back to the dormitories immediately!'

Percy was in his element.

'Follow me! Stick together, first-years! No need to fear the troll if you follow my orders! Stay close behind me, now. Make way, first-years coming through! Excuse me, I'm a Prefect!'

'How could a troll get in?' Harry asked as they climbed the stairs.

'Don't ask me, they're supposed to be really stupid,' said Ron. 'Maybe Peeves let it in for a Hallowe'en joke.'

They passed different groups of people hurrying in different directions. As they jostled their way through a crowd of confused Hufflepuffs, Harry suddenly grabbed Ron's arm.

'I've just thought Hermione.'

'What about her?'

'She doesn't know about the troll.'

Ron bit his lip.

'Oh, all right,' he snapped. 'But Percy'd better not see us.'

Ducking down, they joined the Hufflepuffs going the other way, slipped down a deserted side corridor and hurried off towards the girls' toilets. They had just turned the corner when they heard quick footsteps behind them.

'Percy!' hissed Ron, pulling Harry behind a large stone griffin.

Peering around it, however, they saw not Percy but Snape. He crossed the corridor and disappeared from view.

'What's he doing?' Harry whispered. 'Why isn't he down in the dungeons with the rest of the teachers?'

'Search me.'

Quietly as possible, they crept along the next corridor after Snape's fading footsteps.

'He's heading for the third floor,' Harry said, but Ron held up his hand.

'Can you smell something?'

Harry sniffed and a foul stench reached his nostrils, a mixture of old socks and the kind of public toilet no one seems to clean.

And then they heard it a low grunting and the shuffling footfalls of gigantic feet. Ron pointed: at the end of a passage to the left, something huge was moving towards them. They shrank into the shadows and watched as it emerged into a patch of moonlight.

It was a horrible sight. Twelve feet tall, its skin was a dull, granite grey, its great lumpy body like a boulder with its small bald head perched on top like a coconut. It had short legs thick as tree trunks with flat, horny feet. The smell coming from it was incredible. It was holding a huge wooden club, which dragged along the floor because its arms were so long.

The troll stopped next to a doorway and peered inside. It waggled its long ears, making up its tiny mind, then slouched slowly into the room.

'The key's in the lock,' Harry muttered. 'We could lock it in.'

'Good idea,' said Ron nervously.

They edged towards the open door, mouths dry, praying the troll wasn't about to come out of it. With one great leap, Harry managed to grab the key, slam the door and lock it.

'Yes!'

Flushed with their victory they started to run back up the passage, but as they reached the corner they heard something that made their hearts stop a high, petrified scream and it was coming from the chamber they'd just locked up.

'Oh, no,' said Ron, pale as the Bloody Baron.

'It's the girls' toilets!' Harry gasped.

'Hermione!' they said together.

It was the last thing they wanted to do, but what choice did they have? Wheeling around they sprinted back to the door and turned the key, fumbling in their panic Harry pulled the door open they ran inside.

Hermione Granger was shrinking against the wall opposite, looking as if she was about to faint. The troll was advancing on her, knocking the sinks off the walls as it went.

'Confuse it!' Harry said desperately to Ron, and seizing a tap he threw it as hard as he could against the wall.

The troll stopped a few feet from Hermione. It lumbered around, blinking stupidly, to see what had made the noise. Its mean little eyes saw Harry. It hesitated, then made for him instead, lifting its club as it went.

'Oy, pea-brain!' yelled Ron from the other side of the chamber, and he threw a metal pipe at it. The troll didn't even seem to notice the pipe hitting its shoulder, but it heard the yell and paused again, turning its ugly snout towards Ron instead, giving Harry time to run around it.

'Come on, run, run!' Harry yelled at Hermione, trying to pull her towards the door, but she couldn't move, she was still flat against the wall, her mouth open with terror.

The shouting and the echoes seemed to be driving the troll berserk. It roared again and started towards Ron, who was nearest and had no way to escape.

Harry then did something that was both very brave and very stupid: he took a great running jump and managed to fasten his arms around the troll's neck from behind. The troll couldn't feel Harry hanging there, but even a troll will notice if you stick a long bit of wood up its nose, and Harry's wand had still been in his hand when he'd jumped it had gone straight up one of the troll's nostrils.

Howling with pain, the troll twisted and flailed its club, with Harry clinging on for dear life; any second, the troll was going to rip him off or catch him a terrible blow with the club.

Hermione had sunk to the floor in fright; Ron pulled out his own wand not knowing what he was going to do he heard himself cry the first spell that came into his head: 'Wingardium Leviosa!'

The club flew suddenly out of the troll's hand, rose high, high up into the air, turned slowly over and dropped, with a sickening crack, on to its owner's head. The troll swayed on the spot and then fell flat on its face, with a thud that made the whole room tremble.

Harry got to his feet. He was shaking and out of breath. Ron was standing there with his wand still raised, staring at what he had done.

It was Hermione who spoke first.

'Is it dead?'

'I don't think so,' said Harry. 'I think it's just been knocked out.'

He bent down and pulled his wand out of the troll's nose. It was covered in what looked like lumpy grey glue.

'Urgh troll bogies.'

He wiped it on the troll's trousers.

A sudden slamming and loud footsteps made the three of them look up. They hadn't realised what a racket they had been making, but of course, someone downstairs must have heard the crashes and the troll's roars. A moment later, Professor McGonagall had come bursting into the room, closely followed by Snape, with Quirrell bringing up the rear. Quirrell took one look at the troll, let out a faint whimper and sat quickly down on a toilet, clutching his heart.

Snape bent over the troll. Professor McGonagall was looking at Ron and Harry. Harry had never seen her look so angry. Her lips were white. Hopes of winning fifty points for Gryffindor faded quickly from Harry's mind.

'What on earth were you thinking of?' said Professor McGonagall, with cold fury in her voice. Harry looked at Ron, who was still standing with his wand in the air. 'You're lucky you weren't killed. Why aren't you in your dormitory?'

Snape gave Harry a swift, piercing look. Harry looked at the floor. He wished Ron would put his wand down.

Then a small voice came out of the shadows.

'Please, Professor McGonagall they were looking for me.'

'Miss Granger!'

Hermione had managed to get to her feet at last.

'I went looking for the troll because I I thought I could deal with it on my own you know, because I've read all about them.'

Ron dropped his wand. Hermione Granger, telling a downright lie to a teacher?

'If they hadn't found me, I'd be dead now. Harry stuck his wand up its nose and Ron knocked it out with its own club. They didn't have time to come and fetch anyone. It was about to finish me off when they arrived.'

Harry and Ron tried to look as though this story wasn't new to them.

'Well in that case ...' said Professor McGonagall, staring at the three of them. 'Miss Granger, you foolish girl, how could you think of tackling a mountain troll on your own?'

Hermione hung her head. Harry was speechless. Hermione was the last person to do anything against the rules, and here she was, pretending she had, to get them out of trouble. It was as if Snape had started handing out sweets.

'Miss Granger, five points will be taken from Gryffindor for this,' said Professor McGonagall. 'I'm very disappointed in you. If you're not hurt at all, you'd better get off to Gryffindor Tower. Students are finishing the feast in their houses.'

Hermione left.

Professor McGonagall turned to Harry and Ron.

'Well, I still say you were lucky, but not many first-years could have taken on a full-grown mountain troll. You each win Gryffindor five points. Professor Dumbledore will be informed of this. You may go.'

They hurried out of the chamber and didn't speak at all until they had climbed two floors up. It was a relief to be away from the smell of the troll, quite apart from anything else.

'We should have got more than ten points,' Ron grumbled.

'Five, you mean, once she's taken off Hermione's.'

'Good of her to get us out of trouble like that,' Ron admitted. 'Mind you, we did save her.'

'She might not have needed saving if we hadn't locked the thing in with her,' Harry reminded him.

They had reached the portrait of the Fat Lady.

'Pig snout,' they said and entered.

The common room was packed and noisy. Everyone was eating the food that had been sent up. Hermione, however, stood alone by the door, waiting for them. There was a very embarrassed pause. Then, none of them looking at each other, they all said 'Thanks', and hurried off to get plates.

But from that moment on, Hermione Granger became their friend. There are some things you can't share without ending up liking each other, and knocking out a twelve-foot mountain troll is one of them.

- CHAPTER ELEVEN*

Quidditch