The serpent who came for harry

Callidora Potter was supposed to be just like her twin brother, James.

Instead, the Sorting Hat placed her in Slytherin.

She grew up alongside Severus Snape and Lucius Malfoy, becoming particularly close to both. Severus became her first love, while Lucius became one of her oldest and most fiercely loyal friends. But everything shattered when Severus chose Voldemort, Sirius betrayed James and Lily's location, and James and Lily were murdered.

Callidora never forgave either of them.

After being subjected to years of experimentation by Foxtrot, Callidora emerged with something no witch or wizard was supposed to possess: the ability to speak to Dementors-and command their obedience. Dumbledore quietly ensured that the Ministry kept her away from Harry, believing that her presence would make him a target.

For ten years, Harry grows up knowing only the Dursleys.

Then, on his eleventh birthday, everything changes.

Petunia Dursley is Harry's maternal aunt.

Callidora is his paternal aunt.

And Dumbledore finally decides Harry is old enough to know the truth.

Callidora arrives at Privet Drive expecting to collect a frightened little boy.

Instead, she finds a skinny, neglected eleven-year-old with James's hair, Lily's face, and her own unmistakable Potter eyes.

Harry doesn't know who she is.

Callidora does.

She's his aunt.

And she's about to burn down half the wizarding world to make sure nobody ever hurts him again.

Unfortunately, Harry's arrival at Hogwarts also means Callidora is forced back into the lives of the people she swore she'd never forgive.

Sirius Black.

Severus Snape.

And the latter has a secret Callidora doesn't know.

Severus never stopped loving her.

He just knows she would rather see him dead than ever forgive him.