[Sequel is "The Black Epidemic"] --- Kathrin Alicia Snape, younger sister to Severus Snape, best friend to Narcissa Black, sisterly figure to Lucius Malfoy, and sixth year Slytherin prefect. Perfect life at Hogwarts, right? Wrong. Very, totally, utterly wrong. Kathrin is dating the Gryffindor Quiddich Seeker and bad boy James Potter. What's worse than that? Her brother has no idea she's dating his worst enemy.