She is prefect and Head Girl alongside Tom Riddle. She is pale and thin, with wispy white-blonde hair that falls in her eyes and dark brown eyes that seem sinister when they glint in the firelight. Her house is Slytherin, and few see her authority coming: surely, they say, the staff isn't fooled by her perfect grades and prissiness; surely Dippet realizes she is bound to tangle herself in the Dark Arts; surely he'll regret it later on.
She takes up working in Knockturn Alley when she graduates, down the street from Borgin and Burke's, and maintains close correspondence with longtime friend Tom Riddle. They've suspected this of her, but not of Tom: they say it has to have been her influence that led to his job choice. Tom Riddle is destined for greatness, they say, and is unwise to correspond with the likes of her.
She is related later to a certain Bellatrix Lestrange, both power-hungry and thirsty for blood. When the Dark Lord ascends, they say she will turn to his side any day.
But never is the Dark Mark scratched across her arm.
She takes a liking to Albus Dumbledore, they say, a good year into the reign of He-Who-Must-Not-Be-Named, but the Order is wary of her presence. One Minerva McGonagall pleads to Dumbledore that she not have deep involvement, but she changes her mind when she proves herself worthy.
She betrays to the Order everything she knows of Voldemort from when he called himself Tom Riddle: she was his closest confidant and knows the most. She tells them that his weakness is a fear of death, emphasizes that he will stop at nothing to stay in power.
When Barty Crouch Sr. authorizes the use of the Unforgivable Curses against Death Eaters, she is the first to take advantage. She wants to be the one to torture them, they say, she wants to see them suffer; she wants to be the one to bring down the Dark Lord. The Imperius Curse is worthless to her, but she makes ample use of the Cruciatus; just as the Longbottoms are later tortured into insanity, she is merciless with her victims, intent, they say, on fighting fire with fire.
She kills her first Death Eater at the age of forty-three and only regrets that she didn't do it sooner.
They say she calls him Riddle in mockery, to infuriate him as best as she can before her death, for she knows she will die sooner or later. She tells them he knows she's betrayed him, he knows she's a threat to him, and he won't stand for it much longer.
It is when she kills one from his inner circle that he comes after her.
Dumbledore offers to protect her, but she declines. She knows she won't kill him, they say, but she'll do her best.
She tries and does, but it is not enough.
Lord Voldemort kills Dorcas Meadowes when she is the age of fifty, a year before he falls for the first time.
They say she's waiting.