Disclaimer: Harry Potter is not mine. And I borrowed the tiniest bit of dialogue from 'The Prince's Tale.'

Note: Just a very short oneshot about Lily and Snape's friendship. I started writing it a while ago, but decided to finish it because my Pottermore Welcome email still hasn't arrived and I need something Potter-related to keep me busy. Anyway, enough moaning – enjoy! :)

Ghosts

"The castle is over a thousand years old!"

This was how they had spent the last few days: Severus talking endlessly, more than he had talked in all his life, and Lily looking increasingly amazed with each new revelation about their world. They were sat at the riverside amongst fallen leaves and twigs beneath a canopy of trees. A shaft of sunlight had broken through the branches, illuminating Lily's pale face. Severus thought he saw the briefest flicker of fear cross it.

He felt his face flush and he looked down. What had he done now? She had only just forgiven him for dropping a tree branch on her interfering sister's head.

When he looked up, Lily was twisting her dark red hair around her finger. "My great aunt had an old house," she said. "Not that old, but maybe a hundred years. It – don't laugh, Sev – "

" – I won't!"

" – But I sometimes thought it was – it was haunted." Her cheeks blushed pink as she said it. "I know it's silly. But it went so cold and there were these creaks and moans – " Lily shivered even though it was a perfectly warm summer's afternoon. "I just don't like old places," she explained. "Hogwarts isn't, um - ?"

"Haunted?" Severus said slowly.

"Do think it could be?" she asked.

Could be? Severus stared at her, truly dumbstruck for the first time in ages. Should he lie? He knew full well that Hogwarts was full of ghosts; he'd read his mother's battered copy of Hogwarts: A History a hundred times over in anticipation. He didn't have to worry about lying, however; apparently, his face had said it all.

"It is, isn't it?" Lily said, anguished.

"Well... each house – remember I told you about the houses? – well, they have their own ghost. But really, honestly, they're not scary, Lily. They're just like us. Just people. Transparent people... that float..." He trailed off. "There's nothing to be scared of."

Lily still looked nervous, but curious too, now. She smiled, clearly trusting him.

Severus wondered how her face would change if he mentioned Inferi – strange, fearsome creatures he'd read about in another book swiped from his mother. If ghosts alone could frighten her, then Inferi would horrify her. They scared him, too, but not half as much as they fascinated him. Then, there were Dementors. He'd told her that they guarded Azkaban, but not what they could do, how they were supposed to feel... She was already worried that they would take her away if she did unauthorised magic; she shied from darkness.

He cast around for something to take her mind off ghosts. "There are supposed to be unicorns in the Forbidden Forest. But they're shy. And then in the lake, I heard there's a Giant Squid!"

Lily giggled. "Yeuch!"

Severus felt the tension he had been holding in his chest dissolve. Gathering steam, he continued to reel off the secrets of their shared world, until –

"Dragons? No way." Her eyes were as wide as Galleons. "Dragons... really?"

"Yes. They're real," said Severus leaning back. A slow and newly confident smile was spreading across his face. "Would I lie to you?"

"No. I know that," she said without hesitation, "only... if there are dragons out there then how come no one ever sees them?"

"They live in the mountains. There are even dragons in Britain. No one sees them, really. And if they did..." He shrugged. "There are Memory Charms for that."

He had said the wrong thing again, but what exactly he wasn't sure. He watched curiously as her smile faded slightly. "Memory Charms?" she asked.

"They make a person forget what just happened..."

Lily's green eyes went round again, but not with excitement this time. "Oh," she said in a flat voice, and she started twirling a strand of hair around her finger, her forehead creased in thought. It was like she was discovering that it wasn't all fairies and unicorns and dragons. There was a dark side, too.

"Does it make a difference, being Muggle born?"

Severus hesitated.

"No," he said. "It doesn't make any difference."

But he had hesitated. It was only a brief pause, but it may as well have been a lifetime.

"Tell me about Hogwarts again, Sev," Lily asked. "Tell me more about the houses."

Severus smiled, relieved at the change in topic. "Okay." He started talking like before, more than he had talked in all his life.

But her expression and her words still nagged at him.

Their world was both a fairytale and a nightmare all at once. And he wasn't just thinking about ghosts anymore.