The Secret of the Sivrils (Harry Potter fanfiction)

A Harry Potter fanfiction based in J K Rowling's world and with some of her characters. This is the sequel to "Diary of a Slytherin (Not Tom Riddle's)". 17-year-old Catherine Carrow is a Slytherin with an infamous dark wizard family name, though she strives to do good. She and her siblings begin seeking more of the mysterious magical objects known as 'Sivrils' hidden around the school. Each one has a different power. Catherine fears the return of a terrible enemy, but maybe with the power of the Sivrils, she can defeat him once and for all.