For as long as Dr. Blythe can remember, she has never been alone. A second consciousness has lived beside her own, sharing her thoughts, her memories, and the body they have never truly called their own. While the rest of London whispers of curses and madness, Blythe has spent years searching for a scientific explanation—and one impossible solution. Separate them. When her experiment succeeds, Vera is finally free to exist as her own woman. She can breathe with her own lungs, walk beneath the rain, and build the life she has always dreamed of beyond the walls of Blythe's laboratory. It is everything Blythe wanted for her. Until Vera leaves. What begins as quiet concern soon becomes something darker. Blythe watches from a distance as Vera falls in love, changes in ways she cannot understand, and becomes someone Blythe no longer recognizes. Desperate to reclaim what they once shared, Blythe finds herself crossing lines she once believed untouchable, mistaking obsession for devotion and possession for love. As Vera begins to unravel beneath the weight of the darkness she can no longer hide, Blythe is forced to decide whether love means saving someone from their worst self—or loving them enough to stay when the monster finally emerges.