A wealthy couple had three daughters, each as beautiful as the night and puissant as the sun. The eldest of these was named Bellatrix.
Her parents were traditional in the way that means “hidebound” and “xenophobic” and “heartless” to those who do not share the same traditions.
Bellatrix was dutiful, as eldest children often are. When she and her sisters came of age each married. Andromeda married badly and left forever, her name burnt from the family tree. Narcissa and Bellatrix married well. This responsibility met, Bellatrix was true to her name and joined the greatest conflict of her generation. Even masked and cloaked her voice gave her away, for her companions in torture and terrorism were almost entirely men.
Her sister - the only sister she had by then, a pair and no longer a trio - stayed at home as her husband went off to maim and massacre with Bellatrix and every young man in their social circle. Bellatrix’s dedication could not be questioned, her skill unassailable, but her choices - there at last was an expectation she could not meet, torn between what wealthy witches did and the promise of her star: unlucky in domestic affairs. quarrelsome and violent. likely to die young.
She was true to her name as she could not help but be. The names of her family were not quite prophecies but were nevertheless binding. She was valued. She was respected, a ferocious tactician and fighter, she and her husband were treasured, were loyal, were true.
It was their downfall. She went with her husband and his brother to torture the Longbottoms and a few days later she stood in court as the boy cried and the other Estranges stood silent and she said “Throw us into Azkaban, we will wait! He will rise again and will come for us, he will reward us beyond any of his other supporters! We alone were faithful! We alone tried to find him!”
She spends the next ten years alone in a cell and loses everything. First her voice, from laughing and screaming in turns, then her hope, then her mind. When she leaves nothing matters, not her husband, not the glory she had expected. All that is left is her cause. If before Azkaban she was loyal and determined afterwards there is just service to her lord, and inflicting pain, and only the tiniest bit of straightforward selfishness left at the heart of her. She wants to live. She wants Narcissa to do the same. All other attachments are burnt away, leaving only unflinching dedication.
The Lestrange brothers fall away from her life, and from their place as her equals in the Death Eaters, and from public notice as though the three are all the same. She is a meteor and all eyes are on her.
She is no longer a person, the eldest daughter of the house of Black. She’s a monster set to frighten children and innocents, her image inescapable once she is out of prison. She is a force of nature, her excesses feared by allies nearly as much as by enemies. She is death, killing everything she touches, blazing too hot, laughing too long, wasting until she is only bones and power and hate.
At the Battle of Hogwarts the world is a bonfire and she is burning at its center, dueling three witches at once and she laughs -
and she falls -
They tell her story for a hundred years and more, the demon driven by love for an evil human man, and in every telling she is less and less a person until she bears no resemblance at all to the evil human woman she once was.