On the train, unknown to any of the trio, to Sirius, or to Remus, there was a certain treacherous rat sitting shivering in Ron's top pocket, terrified. He knew he had to be extra careful not to be seen now, he knew even after all this time Moon - Lupin would still be able to recognise him. In fact, it was a miracle he hadn't already smelt him. It must not be close to Full Moon. It had been a long time since he had religiously kept track of the moon cycle with the other Marauders. Stop it. Not the other Marauders. You are no longer part of the Marauders. You are no longer part of anything. For a moment, Pettigrew almost felt sad, before determinedly shaking himself out of it. If he was to survive, he couldn't think longingly of the past.

…

Remus uncertainly took a seat in the compartment with Harry's friends. Although he obviously wanted to stay close to Harry, and get to know Harry's friends, he didn't know whether Harry would want him around when he had his friends to talk to, and would Harry's friends want a Professor in the compartment? But Harry had always been a unique, unusual boy, and his friends seemed much the same. Well, Hermione seemed enthusiastic to ask questions about lessons, in fact, scarily enthusiastic. Remus saw the two boys exchange amused, knowing looks. Ron seemed less enthusiastic, but Harry's good words about him seemed to quell any doubts about having a Professor in their compartment.

During the journey, Remus noticed a strange, half familiar smell. It left Remus almost wishing it was nearer the Moon, so he would know what it was, because as it was, the smell was driving him mad. He couldn't place it, and yet, he knew he knew it. He shook it his head. It wasn't important. Actually, knowing his luck it would be … OK. Now he was getting paranoid. Mad Eye would be proud.

Mid afternoon, just as it had started to rain, blurring the rolling hills outside the window, they heard footsteps in the corridor, and three people appeared at the door: Draco Malfoy, flanked, as usual, by his cronies, Crabbe and Goyle, who seemed to exist to do Malfoy's bidding.

Remus scented trouble as soon as the pale boy with the pointed, sneering face appeared at the door. Although he wasn't entirely sure who the boy was, he could tell he wasn't here to exchange friendly greetings, and Harry, Ron and Hermione's posture and expressions had immediately become hostile. Remus would be willing to bet money that the boy was Malfoy.

"Well look who it is," said Malfoy in his usual lazy drawl, "Potty and the Weasel." Crabbe and Goyle chuckled trollishly,

"Clever," said Harry, "did you come up with that one all by yourself, or did Daddy have to help you?"

Remus chose this moment to intervene, knowing that if he did not, a fight would erupt, "I hope there's no trouble boys?" he said in his normal light tone, knowing full well that there was always trouble between these two boys,

"Who are you?" asked Malfoy, taking the moment to eye Remus' new robes. Sirius had insisted on treating Remus in honour of the occasion. Remus had insisted on nothing too expensive. Obviously the robes didn't meet Malfoy's standards and he barely repressed a sneer, obviously realising he was lucky not to be in trouble. This didn't bother anybody in the compartment; it wasn't like they cared what Malfoy thought.

"I am your new Defence Against the Dark Arts teacher. Professor Lupin, pleased to meet you. And you are?"

"Draco Malfoy. We'll … just be going now,"

"Pleased to hear it,"

Ron was looking at Remus with a new respect (Hermione had already given him the respect she automatically gave all teachers) anybody who put down Malfoy deserved respect in his book. Remus gave Ron a small smile. The rain thickened as the train sped yet further north, which gradually darkened until the lanterns flickered into life all along the corridors and over the luggage racks. The train rattled, the rain hammered, and the wind roared. Harry felt curiously uneasy. It wasn't the bad weather that bothered him, though, obviously, that wasn't pleasant, but Harry had never felt the train shake this much before. Harry knew it had to be just the wind, but he had always relied on his instincts: they had never let him down before and now he couldn't shake the feeling that something was definitely wrong.

The train started to slow down. "Brilliant," said Ron, getting up to try and see outside. "I'm starving, I want to get to the feast …"

"We can't be there yet," said Hermione, checking her watch.

"So why're we stopping?"

The train was getting slower and slower. Remus kept silent, but exchanged a glance with Harry. His eyes were alert and wary. He had a nasty feeling that they would shortly be meeting the Dementors, and now he was not overly sure he could handle them. The train came to a stop with a jolt and distant thuds and bangs told them that luggage had fallen out of the racks. Then, without warning, all the lamps went out and they were plunged into total darkness.

"What's going on?" said Ron's voice from behind Harry,

"It must be the Dementors," said Remus, speaking up for the first time and conjuring a handful of flames, lighting the compartment.

"Dementors? What are they doing here?" said Ron, worried,

"They are searching the train for Sirius Black. Stay behind me," but before Remus could move any further the compartment door suddenly opened and Neville fell painfully over Harry's legs.

"Sorry. D'you know what's going on? Ouch! Sorry-"

"Hullo Neville," said Harry, pulling Neville up by his cloak. The door slid open again and Ginny appeared. Once again Remus had to explain what was going on to the two newcomers, before getting up to talk to the driver.

Before he could reach the door, however, it slid open. Illuminated by the shivering flames in Remus' hand was a cloaked figure that towered to the ceiling. Its face was completely hidden beneath its hood. Harry felt an odd sort of detached curiosity, So this must be a Dementor. Harry's eyes darted downwards, and immediately wished they hadn't. There was a hand protruding from the cloak, greyish and glistening, like something dead that had decayed in water …

It was visible only for a split second. As though the Dementor had sensed Harry's gaze, the hand was suddenly withdrawn into the folds of the rippling black material. And then the Dementor drew a slow, rattling breath, as though it was trying to suck something more than air from its surroundings.Harry had only ever heard Sirius talk once about Azkaban, but the memory of it had had such an impact that Harry recognised the Dementor's actions. He didn't have time to react to the knowledge though.

An intense cold swept over them all, wiping all other thoughts from Harry's mind. He felt his breath catch in his chest. The cold went deeper than his skin, No ... can't give in. But it was no good. The cold was inside his chest. It was inside his very heart …

Harry's eyes rolled up into his head. He couldn't see. He was drowning in cold. There was a rushing in his ears as though of water. Distant voices. Panicked voices. He was being dragged downwards, the roaring growing louder, ever louder …

And then, from far away, he heard a screaming, terrible, terrified, pleading screams. He wanted to help whoever it was, he tried to move his arms, but couldn't … a thick white fog was swirling around him, inside him-

"Harry! Harry! Wake up!"

"W-what?"

Harry opened his eyes. There were lanterns above him, and the floor was shaking – the Hogwarts Express was moving again and the lights had come back on. He had slid out of his seat onto the floor. His mind was confused. Ron, Hermione and Remus were all kneeling beside him. When he put his hand to push his glasses back on he felt drenched in cold sweat and he couldn't stop shivering.

Ron and Hermione heaved him back onto the seat.

"Are you OK?" Ron asked nervously.

"Yeah," Harry replied. Nobody in the compartment looked like they believed him. After all 'I'm fine' was the lie he most often told. "Who screamed?"

"No one screamed," said Ron, more nervously still. Harry slowly remembered what he had learnt about the effects of Dementors, and the scream … but it couldn't have been, he couldn't have been remembering the final moments of …

Hermione reached out a sympathetic hand, but before she could reach him, he snapped, "Don't touch me! Don't look at me!" and retreated into a corner. Ron and Hermione looked shocked, but they were thankfully distracted by Remus breaking a block of chocolate into pieces. As he gave Harry a particularly large piece he gave him an understanding look, letting him know that he too had figured out who was screaming.

"Eat it. It'll help."

Harry took the chocolate, but didn't eat it. Everyone stared at him. Remus crumpled up the empty chocolate wrapper and put it in his pocket. "I need to speak to the driver, excuse me, Harry," he seemed reluctant to go but walked past Harry and disappeared into the corridor.

"I – I thought you were having a fit or something, but Professor Lupin said it was because of the Dementor," said Ron, who still looked scared. "You went sort of rigid and fell out your seat and started twitching-"

"And Professor Lupin stepped over you and walked towards to Dementor and pulled out his wand, said Hermione. "And he said, 'None of us is hiding Sirius Black under our cloaks. Go.' But it the Dementor didn't move, so Lupin muttered something and a silvery thing shot out of his wand and it sort of glided away …"

"It was horrible," said Neville, in a higher voice than usual. "Did you feel how cold it went when it came in?"

"I felt weird," said Ron, shifting uncomfortably. "Like I'd never be cheerful again …" Ginny was huddled in the corner looking nearly as bad as Harry. Her eyes were wide open like she was afraid to close them. Harry supposed that she too had been remembering things she would rather forget. She gave a choked sob that she had been trying to hold in and Hermione went over and put a comforting arm around her.

"But didn't any of you – fall off your seats?" asked Harry awkwardly, involuntarily glancing at Ginny. Ginny had had the most terrible experience imaginable only last year and yet even she wasn't affected nearly as much as he was. Was he just weak?

"No," said Ron, looking anxiously at Harry again and drawing Harry from his thoughts. "Ginny was shaking like mad though …" glancing, worried, at his little sister.

Remus reappeared at the doorway. He paused as he entered, looked around and gave a small smile, "I haven't poisoned that chocolate you know …"

Harry felt slightly comforted by Remus' familiar humour. Harry took a bite of the chocolate and felt a warmth spread to tips of his fingertips and toes. "We'll be at Hogwarts in ten minutes. Are you all right Harry?" Harry gave a single tired nod and began to feel slightly comforted as they arrived at the familiar scene of Hogwarts.