It was the start of the spring term, just after the New Year, and the boys of Slytherin had claimed their usual compartment in the Hogwarts Express—the one far at the back, with its frosted glass door and worn green seats no one dared contest them for.

Draco Malfoy lounged near the window, legs stretched, looking bored. Blaise Zabini flipped through a magazine, occasionally scoffing at whatever didn’t meet his standard. Lorenzo Berkshire was mid-rant about something Regulus Black had said, while Regulus leaned back, smug and unbothered, tossing Bertie Bott’s Every Flavour Beans into his mouth like he had nothing better to do.

Tom Riddle sat in the corner with a book open but long forgotten, his eyes half-lidded in thought. And next to him, Mattheo—his younger brother, less composed, more volatile—drummed his fingers along the edge of the seat, his leg bouncing restlessly.

They were all there.

Except Theodore Nott.

He’d vanished just as they were boarding. Said nothing. No explanation. Not even to Mattheo, and that was saying something. The two had grown up side by side—matching tempers, matching secrets. But not this one.

“Where the hell is he?” Mattheo muttered under his breath, checking his watch.

“Probably went to hex someone before the term even begins,” Blaise offered without looking up.

“Or he’s avoiding another letter from his father,” Regulus added dryly.

But before any of them could offer a better theory, the compartment door slid open with a clean click.

There he was.

Theodore.

And he wasn’t alone.

He stepped in first, one hand holding the strap of a small, pale-yellow bag—definitely not his. Behind him came a girl. Hufflepuff robes. Tie slightly crooked. A quiet kind of presence. And yet, the entire room paused.

She was… familiar and unfamiliar all at once. Delicate, softer around the edges. Like she belonged in a sun-drenched meadow, not here in a den of serpents.

And Theodore Nott—sharp-tongued, sharp-jawed, perpetually unimpressed—was guiding her. Not dragging, not pushing, not scowling like usual. He guided her. Eyes constantly flickering down to make sure she was okay, like he was ready to snap at anyone who looked at her wrong.

The bag he held wasn’t slung over his shoulder in lazy disgust. He was holding it—actually holding it—like it mattered.

Draco’s eyebrows shot up.

“Is that—?”

“No way,” Lorenzo breathed, blinking slowly.

Regulus sat forward now, the lazy calm gone, curiosity peaking. Even Tom looked up from his book, gaze sharp and unreadable.

But Mattheo... Mattheo didn’t say anything. He didn’t have to.

Because the moment the girl stepped into the room, his eyes locked on her. She wasn’t his type—not by a long shot. She had kindness written into the corners of her mouth, sweetness in her walk, and something heartbreakingly gentle behind her eyes.

Mattheo preferred fire. Something rough around the edges. Not… this.

But still.

Something inside him pulled tight.

He shouldn't be staring. She was Theodore’s sister. His best friend’s little sister. Practically forbidden territory. He shouldn’t be thinking anything beyond “Oh, right, Nott’s got a sister”—and yet, there he was.

His gaze didn’t just linger.

It burned.

Theodore sat beside her, protective and silent. His posture screamed one thing to the boys without needing words: Don’t.

Don’t ask. Don’t look. Don’t even think about it.

But it was too late.

Because Mattheo’s jaw had gone tight, and his usual smirk was gone. Replaced by something quieter. Something more dangerous.

And in the silence that followed, something shifted between them all—subtle but undeniable.

The younger Nott was no longer a secret.

And Mattheo Marvolo Riddle had just found his newest obsession.