Disclaimer: I Do Not Own Harry Potter.
Cassia Weasley and Emilia Malfoy had been friends since they were small. Their parents were close and expected their children to be also.
Cassia had been sorted into Gryffindor and Emilia into Slytherin, but that hadn't effected either girl.
All through their years at Hogwarts their friendship remained strong it was a year after they had finished their schooling that friendship turned sour.
Emilia had married Corvus Black; he was thirty and had been Cassia and Emilia's potions professor at Hogwarts.
Emilia had been eighteen, smart and beautiful and from a good pureblood family everything that a pureblood wizard should want in a wife.
Except Corvus wanted the unmarried Cassia too, and she wanted him.
Cassia with her vivid red hair and freckles, pale and so innocent looking the lion that should have been a snake.
Cassia was fine with sharing him for a few months, but not forever.
It was an accident, Emilia had fallen down the stairs or at least, that's what she told everyone.
She swore it with an emotionless expression to Corvus when he found Emilia dead at the moment of the stairs and Cassia standing over her.
She whispered it to him on their wedding night, and he pretended to believe his beautiful Cassia.