Katherine Greystone disappeared from Hogwarts for nearly an entire year after years of torment inside Slytherin House shattered her completely. Once the quiet, intelligent girl everyone envied and destroyed, she returns at the beginning of seventh year colder, more powerful, and deeply changed by whatever happened during her disappearance. As ancient magic awakens beneath Hogwarts and fear spreads through the castle, the same people who helped ruin her — Draco Malfoy, Theodore Nott, Blaise Zabini, Pansy Parkinson, Daphne Greengrass, and especially Mattheo Riddle — are forced to face the consequences of what they created. But while Katherine wants revenge, Mattheo slowly realizes the girl he spent years hurting is also the girl he can no longer live without.