Prompt: Harry Potter AU (technically a part of my Phoenix Feather and Dragon Heartstring series, but can be read as a stand-alone.)
Helen was the most brilliant witch Nikola had ever known, but there was one spell that often defeated her, during their years as students at Hogwarts and after: the Patronus Charm, and it annoyed her to no end that Nikola was able to perform it nearly flawlessly every time without even seeming to struggle.
Of course, Nikola delighted in teasing her with all sorts of ridiculous possibilities: secret magical libraries in Ravenclaw Tower, guidance from a fairy he'd met on summer holidays, a potion that increased his magical ability and gave him his utterly irresistible tousled hair.
But the truth was that he did have a secret weapon, which had always been and would always be her – simply thinking about Helen, how perfectly content he was in her company, the thrill of excitement that ran through him when they were deep in discussion about magical theory, the warm sparkle of her beautiful blue eyes, all of those things were enough by themselves; and on the day Helen had told him she loved him for the first time, Nikola knew he would never have a more perfect memory.