Surface Pressure

It's been nine years since the Battle of Hogwarts and the wizarding world has been wiped of almost all criminals, thanks to the incredibly hard-working Auror, Harry Potter. With one last remaining Death Eater to catch, they are on the cusp of peace at last.

That is, until Hermione brings reports to Harry concerning a murderous snake whom she believes has something to do with the deceased Dark Lord. She thinks it could be the seventh part of Voldemort's soul, created because he did not know about the (now destroyed) Horcrux that was in Harry. Seven Horcruxes, not seven parts.

Harry finds the snake and feels compelled to assuage some of his survivor's guilt by making the man suffer. He recreates the resurrection ritual, but this time, with a crucial alteration to the ingredients: the flesh of a servant. Without it, the Dark Lord Voldemort has no magic. Harry secretly takes the man prisoner in his home, wanting to hurt him, to force him to divulge where his last Horcrux is, but things begin to rapidly fall out of his control.