tldr: Heir of Gryffindor breaks into some Russian(?) auror department to steal the diary of Tom Riddle because its got information she wants, and she somehow has super lightning bolt speed powers, but they defeat her and strap her to a chair with veritaserum where she tells them about Tom Riddle and some made up stuff about the other descendants of the founders, and the story of him killing Hepzibah Smith for the cup and pinning it on Hokey. The interrogator lets her go and gives her the diary, and then it turns out she was Tom Riddle all along and she changes back into him and kills them. Then a young Igor Karkaroff is walking through the snow for some reason and finds the remains of the og heir of Gryffindor. Idk it lost me a bit at the end