The three new students talked for several hours, finding out everything about each other. They completely lost track of time, especially when the sweets trolley came around with the kindly old lady, and although Lilleth didn't have any money of her own, Piper and Blake bought piles of anything they could see and shared them out.

But, just as it began getting dark outside, there was a jolt and the train came to a stop; distant thuds and bangs told them that luggage had fallen out of the racks, and Lilleth had to grab Mourka from where he was still dozing in a corner to prevent him from being squashed by her own trunk falling down. Then, without warning, all the lamps went out and they were plunged into total darkness.

"What the hell is going on?" said Piper, her voice trembling slightly.

"I have no idea." said Blake, and Lilleth heard him push himself to his feet. He brushed past her as he walked towards the door and pulled it open.

"Do you see anything?" asked Piper.

"No." said Blake in confusion. "I mean, I can't see a thing at all. It's too dark."

"Come sit back down." said Piper; the anxiety clear in her voice as she demanded her brother to return to his seat.

"Hang on." said Lilleth, reaching into her trunk, which was now on the floor. She fumbled for the buckles and managed to undo them after a few seconds, finally able to delve into it. Luckily, near the top she had placed a small muggle torch that she had stolen from the Dursleys to let her read under the covers at night without anyone else seeing, and she found it quite quickly and clicked the button.

The entire compartment was illuminated by the bright white light from the little red torch, and Lilleth shone it around the compartment so they could all see. Piper was squeezing Blake's hand tightly on the sea opposite them – so tightly in fact, that both their knuckles had gone white; Mourka was sat on the floor in front of the glass door to the compartment, his tail waving behind him like a small guard cat. But what shocked Lilleth the most was that the glass on the door and windows had frosted over, as if they had been frozen in time for the three months until snow and a chilly wind usually befell the country.

"Where did that ice come from?" asked Blake, voicing what Lilleth was too confused to say.

"I... have no idea." said Lilleth, furrowing her brows in confusion. "I'm going to go see if there's anything out in the hall."

She took a determined step forward to the door, but it slid slowly open before she could reach it.

Standing in the doorway, illuminated by the torch in her hand, was a cloaked figure that towered to the ceiling. Its face was completely hidden beneath its hood. Lilleth's eyes and the direction of the light from the torch darted downwards, but she regretted it at once, as what she saw made her stomach contract. There was a hand protruding from the cloak and it was glistening, greyish, slimy-looking and scabbed, like something dead that had decayed in water.

Piper let out a small shriek and buried her face in her brother's shoulder, quivering with fear, and Blake had gone ashen-faced. Lilleth stumbled backwards, suddenly finding herself with a need to get as far away from the creature as possible.

And then, the thing beneath the hood, whatever it was, drew a long, slow, rattling breath, as though it was trying to suck something more than air from its surroundings. An intense cold swept over them all. Lilleth felt her own breath catch in her chest. The cold went deeper than the skin. It was inside her chest, inside her very heart.

Time seemed to freeze where they were as the creature stared around at them. All Lilleth wanted to do was turn off her torch, plunge them back into darkness so they didn't have to look at it, or to make it leave, or to leave herself, but she was rooted to the spot, unable to move a muscle despite the frigid feeling of cold that was filling her bones.

All happy thoughts of becoming friends with Blake and Piper instantly blew out of her mind. Why would anyone want to be friends with her? She was pathetic, she was weak – she was alone. She had no one, nor would she ever. Even Harry didn't want her.

After what seemed an age, the creature pulled away and the door once again slid closed.

No one moved. Even Mourka, who was still sat on the floor, had his tail pointed straight back like a fire poker, his eyes completely still. For a moment, Lilleth thought he had been frozen into a block of cat-ice.

Before long, the lights came back on and the train rattled into motion. The frost disappeared from the glass, and there was an air of warmth that seemed to have been something that was entirely forgotten during the short time the hooded thing had been there. It was as if nothing had happened at all.

Blake was the first to speak.

"What the bloody hell was that?"

"I have... no idea." said Lilleth shakily, and she finally found movement in her limbs once more and managed to turn off the torch.

"It was scary." said Piper, the tremble in her voice very apparent – not that it looked as if she was trying to hide it.

"Well, at least it's gone now." said Lilleth, trying to put on an optimistic tone, although she wasn't sure it was working.

There was a knock at the door, and they all looked around, fear clenching their chests once again, but luckily, it wasn't the creature again. It was a boy, with soft brown hair and wearing robes with yellow trimmings. On his chest, he wore a yellow badge that said 'prefect' on it. He opened the door and popped his head in.

"Are you three alright?" he asked kindly.

"What was that?" Piper blurted out.

"A dementor." said the boy. "They're guards at the wizard prison, Azkaban. Not very pleasant creatures, but neither is the person they're looking for."

"Who are they looking for?" asked Blake.

"Sirius Black." said the boy with a small grimace. "But don't worry. He won't come anywhere near the school. He wouldn't dare."

Lilleth nodded numbly. It wasn't exactly comforting.

"Anyway, you three are alright?"

They all nodded, still all quite pale.

"Well, we'll be at Hogwarts soon." said the boy. "You should probably get changed into your robes."

"Thank you." said Lilleth, forcing a smile onto her face.