Aurora Sinistra spends most of her time watching the stars. In the summer of 1991, she has a plan redeem the reputation of Slytherin House, and some of the people inside it. Recruiting Severus Snape to help her, the two teachers undertake a gambit of their own that leads the Boy-Who-Lived and the Brightest Witch of Her Age into Slytherin House and friendships with Draco Malfoy.