Ever since they were children, Y/N Riddle has always been around Theodore Nott. Being Mattheo Riddle’s younger sister by only a year meant she spent most of her life trailing after Mattheo and his closest friends, especially Theo. What nobody really talks about is that Y/N used to have the biggest crush on Theo when she was younger. From Theo’s 1st year until Y/N’s 2nd year, she adored him completely before eventually convincing herself she had grown out of it. Theo, meanwhile, didn’t realize when his feelings started changing. Somewhere protecting Y/N and staying close to her stopped feeling like something he did because she was Mattheo’s little sister. It became something he wanted. Something he couldn’t stop thinking about. At first, the group didn’t notice the stolen glances from Theo. They assumed he was keeping up with the protective brother’s best friend role. But Mattheo notices almost immediately when that thin line is crossed. Theo insists he’s only looking out for her because Mattheo would want him to. Mattheo doesn’t believe him, he’s suspected for years that Theo likes his sister, even when Theo didn’t. He constantly teases Theo in subtle ways—small comments muttered only for Theo to hear, but eventually everyone hears except Y/N herself. The rest of the group catches on too, and soon Theo becomes the target of endless very secret teasing whenever he instinctively pulls Y/N away from danger, carries her books, or watches every person who talks to her like they’re a threat. Y/N, however, remains completely oblivious. To her, Theo is just Theo. Quiet, protective, dependable Theo, who always appears when she needs help and always seems to know when she’s uncomfortable before she even says anything.
At the start of the school year, Y/N unexpectedly earns a spot on the Slytherin Quidditch Team after impressing everyone with her natural talent during a challenge at the team’s tryouts. While the rest of the team debates whether she belongs, Theodore Nott finds himself unable to stop thinking about the girl who refused to back down when challenged. As practices and matches bring them together, their relationship becomes a constant mix of sarcastic remarks, lingering glances, and undeniable tension. What starts as reluctant attention slowly grows into something more, forcing both Theo and Y/N to confront feelings neither of them expected.
Y/N transfers from Beauxbatons to Hogwarts for her seventh year with a reputation for being guarded, outspoken, and completely uninterested in boys. While the school quickly becomes captivated by the mysterious new girl, Theodore Nott quietly fixates on her, watching from a distance and learning every detail he can before ever speaking a word to her. Theo finds himself constantly drawn to her presence, quietly yearning for her attention while she remains cautious and unconvinced that he is any different from the rest. What begins as silent observation turns into something much more dangerous when neither of them can ignore the growing connection between them.
Y/N was the sort of person everyone assumed had been sorted into the wrong house. Bright smiles, endless kindness, and a habit of helping anyone who needed it made her seem more like a Hufflepuff than a Slytherin. To everyone around her, Y/N was sunshine wrapped in green and silver. Theodore Nott hated it. Or at least, that was what he told himself. While everyone else continued treating Y/N like Hogwarts' resident sweetheart, Theodore watched her more closely. He started seeing patterns where others saw coincidence. Every conversation, every smile, every perfectly chosen word seemed deliberate. She read rooms better than anyone. What begins as irritation grows into fascination, then tension, then something neither of them can escape. As Theodore falls harder and harder for the girl everyone else underestimates, he discovers the truth about Y/N: she is sunshine with a blade hidden behind her smile. And once he finally accepts every part of her, there is no saving him from falling completely. Especially when she has been quietly unraveling him from the very beginning.
At Hogwarts, everyone knows two things about Y/N and Theodore Nott: they are the smartest students in their year, and they are absolutely insufferable when they're together. For years, they've been locked in an academic rivalry so intense that it's become legendary throughout the castle. It started when they realized they'd finally found someone capable of matching them intellectually. Since then, every exam, essay, classroom debate, and academic achievement has become a competition. Most students are relieved to pass a test. But Theo and Y/N are busy arguing over who scored higher by a single point. What neither of them realizes is that they're paying far more attention to each other than any rivalry should require.
Y/N and Theodore Nott have been inseparable for years, the kind of friends who drift in and out of each other’s homes and lives with an ease that only comes from long‑standing trust. Theo has a reputation for being charming and flirtatious, the sort of person who never seems to take romance seriously, and Y/N has always accepted that as part of who he is. What she doesn’t know is that behind his casual exterior, Theo keeps a private side of himself carefully hidden — a side shaped by his interest in structured, consensual power dynamics and the world of BDSM. He has never shared this with anyone in their circle, least of all Y/N. When Y/N figures out his little secret, instead of being unsettled, she finds herself intrigued by the structure, communication, and trust involved. When she eventually tells Theo she wants to try it, he reluctantly agrees to guide her himself. What begins as an experiment for Y/N and a protective compromise for Theo slowly becomes a shared secret that reshapes the foundation of their relationship.
Everyone knows Theodore Nott is cold, unreadable, and impossible to get close to—except when it comes to Y/N, the one person who grounds him and brings out a rare softness he keeps carefully hidden. When a former Hogwarts student attempts Legilimency on Theo and, for the first time, finds a mind completely closed off to him, that failure sparks an obsession he cannot let go of. Unable to understand or penetrate what he cannot read, he returns to Hogwarts under the guise of research, determined to solve the one mind that refuses him. As strange disturbances begin to follow Theo and Y/N at school, it becomes clear that being unreadable has consequences neither of them could have anticipated.
Mattheo Riddle returns to Riddle Manor after his first year at Hogwarts, bringing his new best friend Theodore Nott with him for the summer, where Theo meets Mattheo’s younger sister for the first time. At ten years old, she has spent the past year hearing about Theo through Mattheo’s stories and letters, and meeting him sparks a quiet, immediate crush that she keeps mostly to herself as she starts watching him from a distance that first summer. From then on, Theo returns to the manor every year, and the three of them grow up side by side, their childhood familiarity slowly turning into something deeper and harder to define as time passes. What begins with a single summer meeting gradually unfolds into a story of growing up together and a bond that shifts over the years, as Theo starts to see her in a way he never did before, just as she tries to convince herself she has already moved on.