'And that complete cow Pansy Parkinson,' said Hermione viciously. 'How she got to be a prefect when she's thicker than a concussed troll…'

'Who are Hufflepuff's?' Harry asked.

'Ernie Macmillan and Hannah Abbott,' said Ron thickly.

Harry lound his attentiveness ebbing, as though his brain was slipping in and out of tune. The quiet that always filled the Hall when Dumbledore was speaking was breaking up as students put their heads together, whispering and giggling. Over on the Ravenclaw table Cho Chang was chatting animatedly with her friends. A few seats along from Cho, Luna Lovegood had got out The Quibbler again. Meanwhile, at the Hufflepuff table Ernie Macmillan was one of the few still staring at Professor Umbridge, but he was glassy-eyed and Harry was sure he was only pretending to listen in an attempt to live up to the new prefect's badge gleaming on his chest.

Harry thought of the sinister winged horses he had seen on the night he had arrived and how Luna had said she could see them too. His spirits sank slightly. Had she been lying? But before he could devote much more thought to the matter, Ernie Macmillan had stepped up to him.

'I want you to know, Potter,' he said in a loud, carrying voice, 'that it's not only weirdos who support you. I personally believe you one hundred per cent. My family have always stood firm behind Dumbledore, and so do I.'

'Er - thanks very much, Ernie,' said Harry, taken aback but pleased. Ernie might be pompous on occasions like this, but Harry was in a mood to deeply appreciate a vote of confidence from somebody who did not have radishes dangling from their ears. Ernie's words had certainly wiped the smile from Lavender Brown's face and as he turned to talk to Ron and Hermione, Harry caught Seamuss expression, which looked both confused and defiant.

First came Neville with Dean and Lavender, who were closely followed by Parvati and Padma Patil with (Harry's stomach did a back-flip) Cho and one of her usually-giggling girlfriends, then (on her own and looking so dreamy she might have walked in by accident) Luna Lovegood; then Katie Bell, Alicia Spinnet and Angelina Johnson, Colin and Dennis Creevey, Ernie Macmillan, Justin Finch-Fletchley, Hannah Abbott, a Hufflepuff girl with a long plait down her back whose name Harry did not know; three Ravenclaw boys he was pretty sure were called Anthony Goldstein, Michael Corner and Terry Boot, Ginny, closely followed by a tall skinny blond boy with an upturned nose whom Harry recognised vaguely as being a member of the Hufflepuff Quidditch team and, bringing up the rear, Fred and George Weasley with their friend Lee Jordan, all three of whom were carrying large paper bags crammed with Zonko's merchandise.

'I'm sure we can find a night that suits everyone,' said Hermione, slightly impatiently, 'but you know, this is rather important, we're talking about learning to defend ourselves against V-Voldemort's Death Eaters -'

'Well said!' barked Ernie Macmillan, who Harry had been expecting to speak long before this. 'Personally I think this is really important, possibly more important than anything else we'll do this year, even with our OWLs coming up!'

He looked around impressively, as though waiting for people to cry 'Surely not!' When nobody spoke, he went on, 'I, personally am at a loss to see why the Ministry has foisted such a useless teacher on us at this critical period. Obviously, they are in denial about the return of You-Know-Who, but to give us a teacher who is trying to actively prevent us from using defensive spells -'

'We think the reason Umbridge doesn't want us trained in Defence Against the Dark Arts,' said Hermione, 'is that she's got some… some mad idea that Dumbledore could use the students in the school as a kind of private army. She thinks he'd mobilise us against the Ministry.'

'Er…' said Zacharias slowly, not taking the parchment that George was trying to pass to him, 'well… I'm sure Ernie will tell me when the meeting is.'

But Ernie was looking rather hesitant about signing, too. Hermione raised her eyebrows at him.

'I - well, we are prefects,' Ernie burst out. 'And if this list was found… well, I mean to say… you said yourself, if Umbridge finds out -'

'You just said this group was the most important thing you'd do this year,' Harry reminded him.

'I - yes,' said Ernie, 'yes, I do believe that, it's just -'

'Ernie, do you really think I'd leave that list lying around?' said Hermione testily.

'No. No, of course not,' said Ernie, looking slightly less anxious. 'I - yes, of course I'll sign.'

Nobody raised objections after Ernie, though Harry saw Cho's friend give her a rather reproachful look before adding her own name. When the last perscfri - Zacharias - had signed, Hermione took the parchment back and slipped it carefully into her bag. There was an odd feeling in the group now. It was as though they had just signed some kind of contract.

That Zacharias bloke's a wart,' said Ron, who was glowering after the figure of Smith, just discernible in the distance.

'I don't like him much, either,' admitted Hermione, 'but he overheard me talking to Ernie and Hannah at the Hufflepuff table and he seemed really interested in coming, so what could I say? But the more people the better really - I mean, Michael Corner and his friends wouldn't have come if he hadn't been going out with Ginny -'

'Here come Ernie and Hannah Abbott,' said Ron, looking over his shoulder. 'And those Ravenclaw blokes and Smith… and no one looks very spotty.'

Hermione looked alarmed.

'Never mind spots, the idiots can't come over here now, it'll look really suspicious - sit down!' she mouthed to Ernie and Hannah, gesturing frantically to them to rejoin the Hufflepuff table. 'Later! We'll - talk - to - you - later!'

Harry walked around the other pairs, trying to correct those who were doing the spell wrong. Ginny was teamed with Michael Corner; she was doing very well, whereas Michael was either very bad or unwilling to jinx her. Ernie Macmillan was flourishing his wand unnecessarily, giving his partner time to get in under his guard; the Creevey brothers were enthusiastic but erratic and mainly responsible for all the books leaping off the shelves around them; Luna Lovegood was similarly patchy, occasionally sending Justin Finch-Fletchley's wand spinning out of his hand, at other times merely causing his hair to stand on end.

'Dumbledore will be back before long,' said Ernie Macmillan confidently on the way back from Herbology, after listening intently to Harry's story. They couldn't keep him away in our second year and they won't be able to this time. The Fat Friar told me -' he dropped his voice conspiratorially, so that Harry, Ron and Hermione had to lean closer to him to hear '- that Umbridge tried to get back into his office last night after they'd searched the castle and grounds for him. Couldn't get past the gargoyle. The Head's office has sealed itself against her.' Ernie smirked. 'Apparently, she had a right little tantrum.'

'Afraid I'm going to have to dock a few points from Gryffindor and Hufflepuff,' he drawled.

'It's only teachers who can dock points from houses, Malfoy,' said Ernie at once.

'Yeah, we're prefects, too, remember?' snarled Ron.

'The Inquisitorial Squad, Granger,' said Malfoy, pointing towards a tiny silver 'I on his robes just beneath his prefect's badge. 'A select group of students who are supportive of the Ministry of Magic, hand-picked by Professor Umbridge. Anyway, members of the Inquisitorial Squad do have the power to dock points… so, Granger, I'll have five from you for being rude about our new Headmistress. Macmillan, five for contradicting me. Five because I don't like you, Potter. Weasley, your shirts untucked, so I'll have another five for that. Oh yeah, I forgot, you're a Mudblood, Granger, so ten off for that.'

'He was bluffing,' said Ernie, looking appalled. 'He can't be allowed to dock points… that would be ridiculous… it would completely undermine the prefect system.'

But Harry, Ron and Hermione had turned automatically towards the giant hour-glasses set in niches along the wall behind them, which recorded the house-points. Gryffindor and Ravenclaw had been neck and neck in the lead that morning. Even as they watched, stones flew upwards, reducing the amounts in the lower bulbs. In fact, the only glass that seemed unchanged was the emerald-filled one of Slytherin.

'Noticed, have you?' said Fred's voice.

He and George had just come down the marble staircase and joined Harry, Ron, Hermione and Ernie in front of the hour-glasses.

Fred and George turned away and disappeared into the swelling crowd descending the stairs towards lunch. Looking highly disconcerted, Ernie muttered something about unfinished Transfiguration homework and scurried away.

She was not the only person acting oddly as the OWLs drew steadily nearer. Ernie Macmillan had developed an irritating habit of interrogating people about their revision practices.

'How many hours d'you think you're doing a day?' he demanded of Harry and Ron as they queued outside Herbology, a manic gleam in his eyes.

'I dunno,' said Ron. 'A few.'

'More or less than eight?'

'Less, I's'pose,' said Ron, looking slightly alarmed.

'I'm doing eight,' said Ernie, puffing out his chest. 'Eight or nine. I'm getting an hour in before breakfast every day. Eights my average. I can do ten on a good weekend day. I did nine and a half on Monday. Not so good on Tuesday - only seven and a quarter. Then on Wednesday -'

Harry was deeply thankful that Professor Sprout ushered them into greenhouse three at that point, forcing Ernie to abandon his recital.

'She clearly wanted to avoid another scene like Trelawney's,' said Ernie Macmillan sagely, squeezing over to join them.

'Hagrid did well, didn't he?' said Ron, who looked more alarmed than impressed. 'How come all the spells bounced off him?'

'It'll be his giant blood,' said Hermione shakily. 'Its very hard to Stun a giant, they're like trolls, really tough… but poor Professor McGonagall… four Stunners straight in the chest and she's not exactly young, is she?'

'Dreadful, dreadful,' said Ernie, shaking his head pompously. 'Well, I'm off to bed. Night, all.'

The journey home on the Hogwarts Express next day was eventful in several ways. Firstly Malfoy, Crabbe and Goyle, who had clearly been waiting all week for the opportunity to strike without teacher witnesses, attempted to ambush Harry halfway down the train as he made his way back from the toilet. The attack might have succeeded had it not been for the fact that they unwittingly chose to stage the attack right outside a compartment full of DA members, who saw what was happening through the glass and rose as one to rush to Harry's aid. By the time Ernie Macmillan, Hannah Abbott, Susan Bones, Justin Finch-Fletchley Anthony Goldstein and Terry Boot had finished using a wide variety of the hexes and jinxes Harry had taught them, Malfoy Crabbe and Goyle resembled nothing so much as three gigantic slugs squeezed into Hogwarts uniform as Harry, Ernie and Justin hoisted them into the luggage rack and left them there to ooze.

`I must say, I'm looking forward to seeing Malfoy's mother's face when he gets off the train,' said Ernie, with some satisfaction, as he watched Malloy squirm above him. Ernie had never quite got over the indignity of Malloy docking points from Hufflepuff during his brief spell as a member of the Inquisitorial Squad.