Disclaimer: Harry Potter is, of course, not mine.

Author's Note: Hello! I've never written any next gen fanfiction before, but the idea fascinates me. I suppose because the possibilities are endless! Some of the common room description is inspired by Pottermore, but it's not overly noticeable. They're around fifth year in this, if you're wondering. I didn't include ages because they never occurred to me for some reason. I don't know what else to say really... I don't where this story came from! But please do read and review; I'd adore some feedback on my first foray into the next generation. :)

Testing the Water

2:03am. A blanket of silence had fallen across the castle. It seemed to grow deeper and more intense as Scorpius Malfoy slipped down the stairs leading off the darkened Entrance Hall. In the dungeons that snaked along deep below the school, the air was stiller and the silence more pronounced. He reached the well-hidden Slytherin common room without bumping in to anyone. The stone wall slid aside – the password was 'dragon hide' – revealing a long, low-ceilinged dungeon room.

It was empty as he had hoped.

"What a waste of time this was!" A young woman materialised beside him, indignantly shrugging off the silvery folds of an Invisibility Cloak. "And after all the effort I went to just to get James to lend it to me. He treats this Cloak like it's his bloody wife, honestly."

Scorpius shrugged. "There may well have been someone down here..." he pointed out. His cool gaze lingered on Rose Weasley as she bent down to stuff the cloak into her satchel. A pink flush crept across her cheeks, clashing spectacularly with her wild, dark red hair. She was annoyed, but Scorpius could only grin. "Anyway, I like the 'cloak and dagger' stuff."

"You're weird," Rose told him firmly. Her blue eyes wandered away from Scorpius, however, and across the strange common room. It was strange to her, at least. Rose lived in a tower, overlooking the treetops of the Forbidden Forest, the sweeping green lawns and the lake in the distance. But here, instead of looking down on the lake, she was... under it?

At her Muggle grandparent's house there was a glass fish tank that ran along one of the oak panelled walls in the dining room. Long-limbed green plants waved out of its dark depths; the fish were silver and orange blurs that hid behind stones and darted under little ceramic bridges. The tank was lit from behind and it made the room shimmer with flickering watery light. This was what Rose remembered when she saw the Slytherin Common Room – it was like floating underwater.

She walked across rugs that had probably lain there for centuries and under the silver lanterns that burned with eerie emerald flames. At the end of the room, there was an ornate stone fireplace on which lay –

"Skulls?" Rose asked, her tone a mixture of curiosity and disdain.

"Yeah, I know." Scorpius shrugged again. He seemed to shrug a lot.

Tall windows framed the fire. Lake water lapped against them, casting a green glow across the dungeon room. In front of the fireplace sat black leather armchairs and sofas. Rose sniggered without meaning to, then quickly fell silent, embarrassed.

"What?" Scorpius stared at her, one eyebrow quirked.

Rose shook her head and chose a seat beneath the green-tinged windows. Scorpius watched her – he watched her curl up on one of the sleek, black sofas and wondered if that was how she sat on the presumably cosier armchairs of Gryffindor Tower. Suddenly, her snigger made sense.

It was Rose's turn to say, "What?" – because Scorpius was staring.

"Nothing," he said. She looked odd with silver and emerald shadows cast over her face – odd, but at the same time kind of striking. Scorpius sat down opposite her, wedging himself in the only available space – a lazy Siamese cat had stretched itself out to sleep.

Rose looked at him in surprise. "I didn't know you had a cat."

"I don't," Scorpius answered, shifting the cat aside. It spread its jaws wide in a yawn and then sauntered off. "It's not mine. We can't have pets at home, anyway. Mother's got allergies."

We are so different, Rose thought, as images of her own home life raced through her head. Owls swooping in and out at all hours, Hugo's toads – he was a strange boy – and the pygmy puffs, which squeaked and rolled incessantly, and had been given to her by her Uncle George presumably to wind up her father. Out of the corner of her eye, she saw Scorpius picking cat hairs off his robes.

So different.

But then, spooky as the dungeon had looked at first glance, there was actually a gothic beauty to it. Granted, she could do without the animal skulls, but the glittering, whooshing sensation of being underwater was soothing, not intimidating. On the surface it felt wrong, yet beneath that it was... not right exactly. Something else. Something unsaid.

"I don't like them either," Scorpius said suddenly, and Rose jumped. She had been vacantly staring at the skulls over the fireplace.

"Be worried if you did." Rose laughed, but it was hushed somehow. A new found shyness had grown to fill the space between them. It was as if now that they had been taken out of neutral territory, they were confused. They were a Slytherin and a Gryffindor – the dungeon reminded them of that – so how were they supposed to behave? There were no rules – nobody had written them yet.

Scorpius wasn't sure whether or not he really knew Rose Weasley. They were friends, but not officially. Their whole relationship hinged on night-time dalliances, meetings in the library – secrets and shadows. No one knew, which felt like a miracle considering the sheer volume of family Rose had at Hogwarts. At first, she seemed to be a Weasley through and through. The Weasley women were strong, intimidating. Scorpius knew that her aunt was Ginny Weasley who'd played for the Holyhead Harpies and, if the legend was true – certainly, his family never mentioned it – her grandmother had killed his Great-Aunt Bellatrix in battle. He didn't care for her cousins so much, but Rose was different. She was popular by default; quiet and thoughtful by nature.

Something dark and hulking glided past the window pane and Rose, deserted by her Gryffindor bravery, screamed. Scorpius leaped up and slipped into the seat beside her. "It's just the Giant Squid," he soothed. "You see all sorts floating past the windows... merpeople sometimes..."

Rose let out an exhausted laugh. She ran a hand through her bushy hair. "Merlin. Frightened by the Giant Squid! Ridiculous..."

"You're not," Scorpius said at once.

Rose stared at him.

The fact that she was a Gryffindor and he a Slytherin barely mattered in a world that had been turned on its head. After all, Rose was a Weasley whose name meant everything and Scorpius was a Malfoy whose name had never meant so little. There was a lingering, hopeful feeling throughout their world that nothing made sense anymore.

Without saying a word, Rose slid her hand across the seat and gripped Scorpius's fingers. He froze, but relaxed after a pause. It was funny – Rose had all the family in the world, but she felt alone amongst them, with the weight of expectation upon her shoulders. Scorpius was an only child, a lonely Slytherin who didn't quite fit, whose name was dirt.

And Rose wondered whether it was their differences that showed just how similar they really were.